diff --git a/Makefile b/Makefile
index fffa15f..eb1fd42 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,18 @@
+.PHONY: t
 t:
-	go test ./... -race -count=1
+	go test ./...
 
+.PHONY: f
 f:
 	go fmt ./...
+
+
+.PHONY: c
+c:
+	go test -race -covermode=atomic ./... -coverprofile=cover.out && \
+# 	go tool cover -html=cover.out && \
+	go tool cover -func cover.out \
+		| grep -vP '[89]\d\.\d%' | grep -v '100.0%' \
+		|| true
+
+	rm cover.out
diff --git a/bucket.go b/bucket.go
index e7e2ab0..df1dc98 100644
--- a/bucket.go
+++ b/bucket.go
@@ -6,18 +6,18 @@ import (
 	"time"
 )
 
-type bucket struct {
+type bucket[T any] struct {
 	sync.RWMutex
-	lookup map[string]*Item
+	lookup map[string]*Item[T]
 }
 
-func (b *bucket) itemCount() int {
+func (b *bucket[T]) itemCount() int {
 	b.RLock()
 	defer b.RUnlock()
 	return len(b.lookup)
 }
 
-func (b *bucket) forEachFunc(matches func(key string, item *Item) bool) bool {
+func (b *bucket[T]) forEachFunc(matches func(key string, item *Item[T]) bool) bool {
 	lookup := b.lookup
 	b.RLock()
 	defer b.RUnlock()
@@ -29,13 +29,13 @@ func (b *bucket) forEachFunc(matches func(key string, item *Item) bool) bool {
 	return true
 }
 
-func (b *bucket) get(key string) *Item {
+func (b *bucket[T]) get(key string) *Item[T] {
 	b.RLock()
 	defer b.RUnlock()
 	return b.lookup[key]
 }
 
-func (b *bucket) set(key string, value interface{}, duration time.Duration, track bool) (*Item, *Item) {
+func (b *bucket[T]) set(key string, value T, duration time.Duration, track bool) (*Item[T], *Item[T]) {
 	expires := time.Now().Add(duration).UnixNano()
 	item := newItem(key, value, expires, track)
 	b.Lock()
@@ -45,7 +45,7 @@ func (b *bucket) set(key string, value interface{}, duration time.Duration, trac
 	return item, existing
 }
 
-func (b *bucket) delete(key string) *Item {
+func (b *bucket[T]) delete(key string) *Item[T] {
 	b.Lock()
 	item := b.lookup[key]
 	delete(b.lookup, key)
@@ -66,9 +66,9 @@ func (b *bucket) delete(key string) *Item {
 // the item from the map. I'm pretty sure this is 100% fine, but it is unique.
 // (We do this so that the write to the channel is under the read lock and not the
 // write lock)
-func (b *bucket) deleteFunc(matches func(key string, item *Item) bool, deletables chan *Item) int {
+func (b *bucket[T]) deleteFunc(matches func(key string, item *Item[T]) bool, deletables chan *Item[T]) int {
 	lookup := b.lookup
-	items := make([]*Item, 0)
+	items := make([]*Item[T], 0)
 
 	b.RLock()
 	for key, item := range lookup {
@@ -92,14 +92,14 @@ func (b *bucket) deleteFunc(matches func(key string, item *Item) bool, deletable
 	return len(items)
 }
 
-func (b *bucket) deletePrefix(prefix string, deletables chan *Item) int {
-	return b.deleteFunc(func(key string, item *Item) bool {
+func (b *bucket[T]) deletePrefix(prefix string, deletables chan *Item[T]) int {
+	return b.deleteFunc(func(key string, item *Item[T]) bool {
 		return strings.HasPrefix(key, prefix)
 	}, deletables)
 }
 
-func (b *bucket) clear() {
+func (b *bucket[T]) clear() {
 	b.Lock()
-	b.lookup = make(map[string]*Item)
+	b.lookup = make(map[string]*Item[T])
 	b.Unlock()
 }
diff --git a/bucket_test.go b/bucket_test.go
index 19266b2..7c8cd06 100644
--- a/bucket_test.go
+++ b/bucket_test.go
@@ -33,7 +33,7 @@ func (_ *BucketTests) DeleteItemFromBucket() {
 
 func (_ *BucketTests) SetsANewBucketItem() {
 	bucket := testBucket()
-	item, existing := bucket.set("spice", TestValue("flow"), time.Minute, false)
+	item, existing := bucket.set("spice", "flow", time.Minute, false)
 	assertValue(item, "flow")
 	item = bucket.get("spice")
 	assertValue(item, "flow")
@@ -42,29 +42,22 @@ func (_ *BucketTests) SetsANewBucketItem() {
 
 func (_ *BucketTests) SetsAnExistingItem() {
 	bucket := testBucket()
-	item, existing := bucket.set("power", TestValue("9001"), time.Minute, false)
+	item, existing := bucket.set("power", "9001", time.Minute, false)
 	assertValue(item, "9001")
 	item = bucket.get("power")
 	assertValue(item, "9001")
 	assertValue(existing, "9000")
 }
 
-func testBucket() *bucket {
-	b := &bucket{lookup: make(map[string]*Item)}
-	b.lookup["power"] = &Item{
+func testBucket() *bucket[string] {
+	b := &bucket[string]{lookup: make(map[string]*Item[string])}
+	b.lookup["power"] = &Item[string]{
 		key:   "power",
-		value: TestValue("9000"),
+		value: "9000",
 	}
 	return b
 }
 
-func assertValue(item *Item, expected string) {
-	value := item.value.(TestValue)
-	Expect(value).To.Equal(TestValue(expected))
-}
-
-type TestValue string
-
-func (v TestValue) Expires() time.Time {
-	return time.Now()
+func assertValue(item *Item[string], expected string) {
+	Expect(item.value).To.Equal(expected)
 }
diff --git a/cache.go b/cache.go
index becf4c6..82c27c2 100644
--- a/cache.go
+++ b/cache.go
@@ -35,37 +35,37 @@ type gc struct {
 	done chan struct{}
 }
 
-type Cache struct {
-	*Configuration
+type Cache[T any] struct {
+	*Configuration[T]
 	list        *list.List
 	size        int64
-	buckets     []*bucket
+	buckets     []*bucket[T]
 	bucketMask  uint32
-	deletables  chan *Item
-	promotables chan *Item
+	deletables  chan *Item[T]
+	promotables chan *Item[T]
 	control     chan interface{}
 }
 
 // Create a new cache with the specified configuration
 // See ccache.Configure() for creating a configuration
-func New(config *Configuration) *Cache {
-	c := &Cache{
+func New[T any](config *Configuration[T]) *Cache[T] {
+	c := &Cache[T]{
 		list:          list.New(),
 		Configuration: config,
 		bucketMask:    uint32(config.buckets) - 1,
-		buckets:       make([]*bucket, config.buckets),
+		buckets:       make([]*bucket[T], config.buckets),
 		control:       make(chan interface{}),
 	}
 	for i := 0; i < config.buckets; i++ {
-		c.buckets[i] = &bucket{
-			lookup: make(map[string]*Item),
+		c.buckets[i] = &bucket[T]{
+			lookup: make(map[string]*Item[T]),
 		}
 	}
 	c.restart()
 	return c
 }
 
-func (c *Cache) ItemCount() int {
+func (c *Cache[T]) ItemCount() int {
 	count := 0
 	for _, b := range c.buckets {
 		count += b.itemCount()
@@ -73,7 +73,7 @@ func (c *Cache) ItemCount() int {
 	return count
 }
 
-func (c *Cache) DeletePrefix(prefix string) int {
+func (c *Cache[T]) DeletePrefix(prefix string) int {
 	count := 0
 	for _, b := range c.buckets {
 		count += b.deletePrefix(prefix, c.deletables)
@@ -82,7 +82,7 @@ func (c *Cache) DeletePrefix(prefix string) int {
 }
 
 // Deletes all items that the matches func evaluates to true.
-func (c *Cache) DeleteFunc(matches func(key string, item *Item) bool) int {
+func (c *Cache[T]) DeleteFunc(matches func(key string, item *Item[T]) bool) int {
 	count := 0
 	for _, b := range c.buckets {
 		count += b.deleteFunc(matches, c.deletables)
@@ -90,7 +90,7 @@ func (c *Cache) DeleteFunc(matches func(key string, item *Item) bool) int {
 	return count
 }
 
-func (c *Cache) ForEachFunc(matches func(key string, item *Item) bool) {
+func (c *Cache[T]) ForEachFunc(matches func(key string, item *Item[T]) bool) {
 	for _, b := range c.buckets {
 		if !b.forEachFunc(matches) {
 			break
@@ -102,7 +102,7 @@ func (c *Cache) ForEachFunc(matches func(key string, item *Item) bool) {
 // This can return an expired item. Use item.Expired() to see if the item
 // is expired and item.TTL() to see how long until the item expires (which
 // will be negative for an already expired item).
-func (c *Cache) Get(key string) *Item {
+func (c *Cache[T]) Get(key string) *Item[T] {
 	item := c.bucket(key).get(key)
 	if item == nil {
 		return nil
@@ -118,10 +118,10 @@ func (c *Cache) Get(key string) *Item {
 
 // Used when the cache was created with the Track() configuration option.
 // Avoid otherwise
-func (c *Cache) TrackingGet(key string) TrackedItem {
+func (c *Cache[T]) TrackingGet(key string) TrackedItem[T] {
 	item := c.Get(key)
 	if item == nil {
-		return NilTracked
+		return nil
 	}
 	item.track()
 	return item
@@ -129,19 +129,19 @@ func (c *Cache) TrackingGet(key string) TrackedItem {
 
 // Used when the cache was created with the Track() configuration option.
 // Sets the item, and returns a tracked reference to it.
-func (c *Cache) TrackingSet(key string, value interface{}, duration time.Duration) TrackedItem {
+func (c *Cache[T]) TrackingSet(key string, value T, duration time.Duration) TrackedItem[T] {
 	return c.set(key, value, duration, true)
 }
 
 // Set the value in the cache for the specified duration
-func (c *Cache) Set(key string, value interface{}, duration time.Duration) {
+func (c *Cache[T]) Set(key string, value T, duration time.Duration) {
 	c.set(key, value, duration, false)
 }
 
 // Replace the value if it exists, does not set if it doesn't.
 // Returns true if the item existed an was replaced, false otherwise.
 // Replace does not reset item's TTL
-func (c *Cache) Replace(key string, value interface{}) bool {
+func (c *Cache[T]) Replace(key string, value T) bool {
 	item := c.bucket(key).get(key)
 	if item == nil {
 		return false
@@ -156,7 +156,7 @@ func (c *Cache) Replace(key string, value interface{}) bool {
 // Note that Fetch merely calls the public Get and Set functions. If you want
 // a different Fetch behavior, such as thundering herd protection or returning
 // expired items, implement it in your application.
-func (c *Cache) Fetch(key string, duration time.Duration, fetch func() (interface{}, error)) (*Item, error) {
+func (c *Cache[T]) Fetch(key string, duration time.Duration, fetch func() (T, error)) (*Item[T], error) {
 	item := c.Get(key)
 	if item != nil && !item.Expired() {
 		return item, nil
@@ -169,7 +169,7 @@ func (c *Cache) Fetch(key string, duration time.Duration, fetch func() (interfac
 }
 
 // Remove the item from the cache, return true if the item was present, false otherwise.
-func (c *Cache) Delete(key string) bool {
+func (c *Cache[T]) Delete(key string) bool {
 	item := c.bucket(key).delete(key)
 	if item != nil {
 		c.deletables <- item
@@ -180,7 +180,7 @@ func (c *Cache) Delete(key string) bool {
 
 // Clears the cache
 // This is a control command.
-func (c *Cache) Clear() {
+func (c *Cache[T]) Clear() {
 	done := make(chan struct{})
 	c.control <- clear{done: done}
 	<-done
@@ -189,7 +189,7 @@ func (c *Cache) Clear() {
 // Stops the background worker. Operations performed on the cache after Stop
 // is called are likely to panic
 // This is a control command.
-func (c *Cache) Stop() {
+func (c *Cache[T]) Stop() {
 	close(c.promotables)
 	<-c.control
 }
@@ -197,7 +197,7 @@ func (c *Cache) Stop() {
 // Gets the number of items removed from the cache due to memory pressure since
 // the last time GetDropped was called
 // This is a control command.
-func (c *Cache) GetDropped() int {
+func (c *Cache[T]) GetDropped() int {
 	return doGetDropped(c.control)
 }
 
@@ -221,7 +221,7 @@ func doGetDropped(controlCh chan<- interface{}) int {
 // now calling SyncUpdates. If other goroutines are using the cache at the same time, there is
 // no way to know whether any of them still have pending state updates when SyncUpdates returns.
 // This is a control command.
-func (c *Cache) SyncUpdates() {
+func (c *Cache[T]) SyncUpdates() {
 	doSyncUpdates(c.control)
 }
 
@@ -234,7 +234,7 @@ func doSyncUpdates(controlCh chan<- interface{}) {
 // Sets a new max size. That can result in a GC being run if the new maxium size
 // is smaller than the cached size
 // This is a control command.
-func (c *Cache) SetMaxSize(size int64) {
+func (c *Cache[T]) SetMaxSize(size int64) {
 	done := make(chan struct{})
 	c.control <- setMaxSize{size: size, done: done}
 	<-done
@@ -243,7 +243,7 @@ func (c *Cache) SetMaxSize(size int64) {
 // Forces GC. There should be no reason to call this function, except from tests
 // which require synchronous GC.
 // This is a control command.
-func (c *Cache) GC() {
+func (c *Cache[T]) GC() {
 	done := make(chan struct{})
 	c.control <- gc{done: done}
 	<-done
@@ -253,25 +253,25 @@ func (c *Cache) GC() {
 // by the worker goroutine. It's meant to be called periodically for metrics, or
 // from tests.
 // This is a control command.
-func (c *Cache) GetSize() int64 {
+func (c *Cache[T]) GetSize() int64 {
 	res := make(chan int64)
 	c.control <- getSize{res}
 	return <-res
 }
 
-func (c *Cache) restart() {
-	c.deletables = make(chan *Item, c.deleteBuffer)
-	c.promotables = make(chan *Item, c.promoteBuffer)
+func (c *Cache[T]) restart() {
+	c.deletables = make(chan *Item[T], c.deleteBuffer)
+	c.promotables = make(chan *Item[T], c.promoteBuffer)
 	c.control = make(chan interface{})
 	go c.worker()
 }
 
-func (c *Cache) deleteItem(bucket *bucket, item *Item) {
+func (c *Cache[T]) deleteItem(bucket *bucket[T], item *Item[T]) {
 	bucket.delete(item.key) //stop other GETs from getting it
 	c.deletables <- item
 }
 
-func (c *Cache) set(key string, value interface{}, duration time.Duration, track bool) *Item {
+func (c *Cache[T]) set(key string, value T, duration time.Duration, track bool) *Item[T] {
 	item, existing := c.bucket(key).set(key, value, duration, track)
 	if existing != nil {
 		c.deletables <- existing
@@ -280,16 +280,16 @@ func (c *Cache) set(key string, value interface{}, duration time.Duration, track
 	return item
 }
 
-func (c *Cache) bucket(key string) *bucket {
+func (c *Cache[T]) bucket(key string) *bucket[T] {
 	h := fnv.New32a()
 	h.Write([]byte(key))
 	return c.buckets[h.Sum32()&c.bucketMask]
 }
 
-func (c *Cache) worker() {
+func (c *Cache[T]) worker() {
 	defer close(c.control)
 	dropped := 0
-	promoteItem := func(item *Item) {
+	promoteItem := func(item *Item[T]) {
 		if c.doPromote(item) && c.size > c.maxSize {
 			dropped += c.gc()
 		}
@@ -351,11 +351,11 @@ drain:
 // blocking. If some other goroutine sends an item on either channel after this method has
 // finished receiving, that's OK, because SyncUpdates only guarantees processing of values
 // that were already sent by the same goroutine.
-func doAllPendingPromotesAndDeletes(
-	promotables <-chan *Item,
-	promoteFn func(*Item),
-	deletables <-chan *Item,
-	deleteFn func(*Item),
+func doAllPendingPromotesAndDeletes[T any](
+	promotables <-chan *Item[T],
+	promoteFn func(*Item[T]),
+	deletables <-chan *Item[T],
+	deleteFn func(*Item[T]),
 ) {
 doAllPromotes:
 	for {
@@ -379,7 +379,7 @@ doAllDeletes:
 	}
 }
 
-func (c *Cache) doDelete(item *Item) {
+func (c *Cache[T]) doDelete(item *Item[T]) {
 	if item.element == nil {
 		item.promotions = -2
 	} else {
@@ -391,7 +391,7 @@ func (c *Cache) doDelete(item *Item) {
 	}
 }
 
-func (c *Cache) doPromote(item *Item) bool {
+func (c *Cache[T]) doPromote(item *Item[T]) bool {
 	//already deleted
 	if item.promotions == -2 {
 		return false
@@ -409,7 +409,7 @@ func (c *Cache) doPromote(item *Item) bool {
 	return true
 }
 
-func (c *Cache) gc() int {
+func (c *Cache[T]) gc() int {
 	dropped := 0
 	element := c.list.Back()
 
@@ -423,7 +423,7 @@ func (c *Cache) gc() int {
 			return dropped
 		}
 		prev := element.Prev()
-		item := element.Value.(*Item)
+		item := element.Value.(*Item[T])
 		if c.tracking == false || atomic.LoadInt32(&item.refCount) == 0 {
 			c.bucket(item.key).delete(item.key)
 			c.size -= item.size
diff --git a/cache_test.go b/cache_test.go
index c59153f..ab5b9b6 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -17,7 +17,7 @@ func Test_Cache(t *testing.T) {
 }
 
 func (_ CacheTests) DeletesAValue() {
-	cache := New(Configure())
+	cache := New[string](Configure[string]())
 	defer cache.Stop()
 	Expect(cache.ItemCount()).To.Equal(0)
 
@@ -32,7 +32,7 @@ func (_ CacheTests) DeletesAValue() {
 }
 
 func (_ CacheTests) DeletesAPrefix() {
-	cache := New(Configure())
+	cache := New[string](Configure[string]())
 	defer cache.Stop()
 	Expect(cache.ItemCount()).To.Equal(0)
 
@@ -56,7 +56,7 @@ func (_ CacheTests) DeletesAPrefix() {
 }
 
 func (_ CacheTests) DeletesAFunc() {
-	cache := New(Configure())
+	cache := New[int](Configure[int]())
 	defer cache.Stop()
 	Expect(cache.ItemCount()).To.Equal(0)
 
@@ -68,17 +68,17 @@ func (_ CacheTests) DeletesAFunc() {
 	cache.Set("f", 6, time.Minute)
 	Expect(cache.ItemCount()).To.Equal(6)
 
-	Expect(cache.DeleteFunc(func(key string, item *Item) bool {
+	Expect(cache.DeleteFunc(func(key string, item *Item[int]) bool {
 		return false
 	})).To.Equal(0)
 	Expect(cache.ItemCount()).To.Equal(6)
 
-	Expect(cache.DeleteFunc(func(key string, item *Item) bool {
-		return item.Value().(int) < 4
+	Expect(cache.DeleteFunc(func(key string, item *Item[int]) bool {
+		return item.Value() < 4
 	})).To.Equal(3)
 	Expect(cache.ItemCount()).To.Equal(3)
 
-	Expect(cache.DeleteFunc(func(key string, item *Item) bool {
+	Expect(cache.DeleteFunc(func(key string, item *Item[int]) bool {
 		return key == "d"
 	})).To.Equal(1)
 	Expect(cache.ItemCount()).To.Equal(2)
@@ -87,13 +87,13 @@ func (_ CacheTests) DeletesAFunc() {
 
 func (_ CacheTests) OnDeleteCallbackCalled() {
 	onDeleteFnCalled := int32(0)
-	onDeleteFn := func(item *Item) {
+	onDeleteFn := func(item *Item[string]) {
 		if item.key == "spice" {
 			atomic.AddInt32(&onDeleteFnCalled, 1)
 		}
 	}
 
-	cache := New(Configure().OnDelete(onDeleteFn))
+	cache := New[string](Configure[string]().OnDelete(onDeleteFn))
 	cache.Set("spice", "flow", time.Minute)
 	cache.Set("worm", "sand", time.Minute)
 
@@ -108,8 +108,8 @@ func (_ CacheTests) OnDeleteCallbackCalled() {
 }
 
 func (_ CacheTests) FetchesExpiredItems() {
-	cache := New(Configure())
-	fn := func() (interface{}, error) { return "moo-moo", nil }
+	cache := New[string](Configure[string]())
+	fn := func() (string, error) { return "moo-moo", nil }
 
 	cache.Set("beef", "moo", time.Second*-1)
 	Expect(cache.Get("beef").Value()).To.Equal("moo")
@@ -119,7 +119,7 @@ func (_ CacheTests) FetchesExpiredItems() {
 }
 
 func (_ CacheTests) GCsTheOldestItems() {
-	cache := New(Configure().ItemsToPrune(10))
+	cache := New[int](Configure[int]().ItemsToPrune(10))
 	for i := 0; i < 500; i++ {
 		cache.Set(strconv.Itoa(i), i, time.Minute)
 	}
@@ -131,7 +131,7 @@ func (_ CacheTests) GCsTheOldestItems() {
 }
 
 func (_ CacheTests) PromotedItemsDontGetPruned() {
-	cache := New(Configure().ItemsToPrune(10).GetsPerPromote(1))
+	cache := New[int](Configure[int]().ItemsToPrune(10).GetsPerPromote(1))
 	for i := 0; i < 500; i++ {
 		cache.Set(strconv.Itoa(i), i, time.Minute)
 	}
@@ -145,7 +145,7 @@ func (_ CacheTests) PromotedItemsDontGetPruned() {
 }
 
 func (_ CacheTests) TrackerDoesNotCleanupHeldInstance() {
-	cache := New(Configure().ItemsToPrune(11).Track())
+	cache := New[int](Configure[int]().ItemsToPrune(11).Track())
 	item0 := cache.TrackingSet("0", 0, time.Minute)
 	for i := 1; i < 11; i++ {
 		cache.Set(strconv.Itoa(i), i, time.Minute)
@@ -164,13 +164,13 @@ func (_ CacheTests) TrackerDoesNotCleanupHeldInstance() {
 
 func (_ CacheTests) RemovesOldestItemWhenFull() {
 	onDeleteFnCalled := false
-	onDeleteFn := func(item *Item) {
+	onDeleteFn := func(item *Item[int]) {
 		if item.key == "0" {
 			onDeleteFnCalled = true
 		}
 	}
 
-	cache := New(Configure().MaxSize(5).ItemsToPrune(1).OnDelete(onDeleteFn))
+	cache := New[int](Configure[int]().MaxSize(5).ItemsToPrune(1).OnDelete(onDeleteFn))
 	for i := 0; i < 7; i++ {
 		cache.Set(strconv.Itoa(i), i, time.Minute)
 	}
@@ -183,7 +183,7 @@ func (_ CacheTests) RemovesOldestItemWhenFull() {
 }
 
 func (_ CacheTests) RemovesOldestItemWhenFullBySizer() {
-	cache := New(Configure().MaxSize(9).ItemsToPrune(2))
+	cache := New[*SizedItem](Configure[*SizedItem]().MaxSize(9).ItemsToPrune(2))
 	for i := 0; i < 7; i++ {
 		cache.Set(strconv.Itoa(i), &SizedItem{i, 2}, time.Minute)
 	}
@@ -192,13 +192,13 @@ func (_ CacheTests) RemovesOldestItemWhenFullBySizer() {
 	Expect(cache.Get("1")).To.Equal(nil)
 	Expect(cache.Get("2")).To.Equal(nil)
 	Expect(cache.Get("3")).To.Equal(nil)
-	Expect(cache.Get("4").Value().(*SizedItem).id).To.Equal(4)
+	Expect(cache.Get("4").Value().id).To.Equal(4)
 	Expect(cache.GetDropped()).To.Equal(4)
 	Expect(cache.GetDropped()).To.Equal(0)
 }
 
 func (_ CacheTests) SetUpdatesSizeOnDelta() {
-	cache := New(Configure())
+	cache := New[*SizedItem](Configure[*SizedItem]())
 	cache.Set("a", &SizedItem{0, 2}, time.Minute)
 	cache.Set("b", &SizedItem{0, 3}, time.Minute)
 	cache.SyncUpdates()
@@ -218,7 +218,7 @@ func (_ CacheTests) SetUpdatesSizeOnDelta() {
 }
 
 func (_ CacheTests) ReplaceDoesNotchangeSizeIfNotSet() {
-	cache := New(Configure())
+	cache := New[*SizedItem](Configure[*SizedItem]())
 	cache.Set("1", &SizedItem{1, 2}, time.Minute)
 	cache.Set("2", &SizedItem{1, 2}, time.Minute)
 	cache.Set("3", &SizedItem{1, 2}, time.Minute)
@@ -228,7 +228,7 @@ func (_ CacheTests) ReplaceDoesNotchangeSizeIfNotSet() {
 }
 
 func (_ CacheTests) ReplaceChangesSize() {
-	cache := New(Configure())
+	cache := New[*SizedItem](Configure[*SizedItem]())
 	cache.Set("1", &SizedItem{1, 2}, time.Minute)
 	cache.Set("2", &SizedItem{1, 2}, time.Minute)
 
@@ -246,7 +246,7 @@ func (_ CacheTests) ReplaceChangesSize() {
 }
 
 func (_ CacheTests) ResizeOnTheFly() {
-	cache := New(Configure().MaxSize(9).ItemsToPrune(1))
+	cache := New[int](Configure[int]().MaxSize(9).ItemsToPrune(1))
 	for i := 0; i < 5; i++ {
 		cache.Set(strconv.Itoa(i), i, time.Minute)
 	}
@@ -278,8 +278,8 @@ func (_ CacheTests) ResizeOnTheFly() {
 }
 
 func (_ CacheTests) ForEachFunc() {
-	cache := New(Configure().MaxSize(3).ItemsToPrune(1))
-	Expect(forEachKeys(cache)).To.Equal([]string{})
+	cache := New[int](Configure[int]().MaxSize(3).ItemsToPrune(1))
+	Expect(forEachKeys[int](cache)).To.Equal([]string{})
 
 	cache.Set("1", 1, time.Minute)
 	Expect(forEachKeys(cache)).To.Equal([]string{"1"})
@@ -314,9 +314,9 @@ func (s *SizedItem) Size() int64 {
 	return s.s
 }
 
-func forEachKeys(cache *Cache) []string {
+func forEachKeys[T any](cache *Cache[T]) []string {
 	keys := make([]string, 0, 10)
-	cache.ForEachFunc(func(key string, i *Item) bool {
+	cache.ForEachFunc(func(key string, i *Item[T]) bool {
 		if key == "stop" {
 			return false
 		}
diff --git a/configuration.go b/configuration.go
index d618215..3267680 100644
--- a/configuration.go
+++ b/configuration.go
@@ -1,6 +1,6 @@
 package ccache
 
-type Configuration struct {
+type Configuration[T any] struct {
 	maxSize        int64
 	buckets        int
 	itemsToPrune   int
@@ -8,14 +8,14 @@ type Configuration struct {
 	promoteBuffer  int
 	getsPerPromote int32
 	tracking       bool
-	onDelete       func(item *Item)
+	onDelete       func(item *Item[T])
 }
 
 // Creates a configuration object with sensible defaults
 // Use this as the start of the fluent configuration:
 // e.g.: ccache.New(ccache.Configure().MaxSize(10000))
-func Configure() *Configuration {
-	return &Configuration{
+func Configure[T any]() *Configuration[T] {
+	return &Configuration[T]{
 		buckets:        16,
 		itemsToPrune:   500,
 		deleteBuffer:   1024,
@@ -28,7 +28,7 @@ func Configure() *Configuration {
 
 // The max size for the cache
 // [5000]
-func (c *Configuration) MaxSize(max int64) *Configuration {
+func (c *Configuration[T]) MaxSize(max int64) *Configuration[T] {
 	c.maxSize = max
 	return c
 }
@@ -36,7 +36,7 @@ func (c *Configuration) MaxSize(max int64) *Configuration {
 // Keys are hashed into % bucket count to provide greater concurrency (every set
 // requires a write lock on the bucket). Must be a power of 2 (1, 2, 4, 8, 16, ...)
 // [16]
-func (c *Configuration) Buckets(count uint32) *Configuration {
+func (c *Configuration[T]) Buckets(count uint32) *Configuration[T] {
 	if count == 0 || ((count&(^count+1)) == count) == false {
 		count = 16
 	}
@@ -46,7 +46,7 @@ func (c *Configuration) Buckets(count uint32) *Configuration {
 
 // The number of items to prune when memory is low
 // [500]
-func (c *Configuration) ItemsToPrune(count uint32) *Configuration {
+func (c *Configuration[T]) ItemsToPrune(count uint32) *Configuration[T] {
 	c.itemsToPrune = int(count)
 	return c
 }
@@ -54,14 +54,14 @@ func (c *Configuration) ItemsToPrune(count uint32) *Configuration {
 // The size of the queue for items which should be promoted. If the queue fills
 // up, promotions are skipped
 // [1024]
-func (c *Configuration) PromoteBuffer(size uint32) *Configuration {
+func (c *Configuration[T]) PromoteBuffer(size uint32) *Configuration[T] {
 	c.promoteBuffer = int(size)
 	return c
 }
 
 // The size of the queue for items which should be deleted. If the queue fills
 // up, calls to Delete() will block
-func (c *Configuration) DeleteBuffer(size uint32) *Configuration {
+func (c *Configuration[T]) DeleteBuffer(size uint32) *Configuration[T] {
 	c.deleteBuffer = int(size)
 	return c
 }
@@ -70,7 +70,7 @@ func (c *Configuration) DeleteBuffer(size uint32) *Configuration {
 // to promote an item on every Get. GetsPerPromote specifies the number of Gets
 // a key must have before being promoted
 // [3]
-func (c *Configuration) GetsPerPromote(count int32) *Configuration {
+func (c *Configuration[T]) GetsPerPromote(count int32) *Configuration[T] {
 	c.getsPerPromote = count
 	return c
 }
@@ -89,7 +89,7 @@ func (c *Configuration) GetsPerPromote(count int32) *Configuration {
 // By turning tracking on and using the cache's TrackingGet, the cache
 // won't evict items which you haven't called Release() on. It's a simple reference
 // counter.
-func (c *Configuration) Track() *Configuration {
+func (c *Configuration[T]) Track() *Configuration[T] {
 	c.tracking = true
 	return c
 }
@@ -97,7 +97,7 @@ func (c *Configuration) Track() *Configuration {
 // OnDelete allows setting a callback function to react to ideam deletion.
 // This typically allows to do a cleanup of resources, such as calling a Close() on
 // cached object that require some kind of tear-down.
-func (c *Configuration) OnDelete(callback func(item *Item)) *Configuration {
+func (c *Configuration[T]) OnDelete(callback func(item *Item[T])) *Configuration[T] {
 	c.onDelete = callback
 	return c
 }
diff --git a/configuration_test.go b/configuration_test.go
index 07c30a7..f5320f9 100644
--- a/configuration_test.go
+++ b/configuration_test.go
@@ -14,7 +14,7 @@ func Test_Configuration(t *testing.T) {
 
 func (_ *ConfigurationTests) BucketsPowerOf2() {
 	for i := uint32(0); i < 31; i++ {
-		c := Configure().Buckets(i)
+		c := Configure[int]().Buckets(i)
 		if i == 1 || i == 2 || i == 4 || i == 8 || i == 16 {
 			Expect(c.buckets).ToEqual(int(i))
 		} else {
diff --git a/go.mod b/go.mod
index ba26803..39b9e4e 100644
--- a/go.mod
+++ b/go.mod
@@ -1,5 +1,7 @@
-module github.com/karlseguin/ccache/v2
+module github.com/karlseguin/ccache/v3
 
-go 1.13
+go 1.18
 
 require github.com/karlseguin/expect v1.0.7
+
+require github.com/wsxiaoys/terminal v0.0.0-20160513160801-0940f3fc43a0 // indirect
diff --git a/item.go b/item.go
index 18d8203..f57b02b 100644
--- a/item.go
+++ b/item.go
@@ -11,8 +11,8 @@ type Sized interface {
 	Size() int64
 }
 
-type TrackedItem interface {
-	Value() interface{}
+type TrackedItem[T any] interface {
+	Value() T
 	Release()
 	Expired() bool
 	TTL() time.Duration
@@ -20,45 +20,25 @@ type TrackedItem interface {
 	Extend(duration time.Duration)
 }
 
-type nilItem struct{}
-
-func (n *nilItem) Value() interface{} { return nil }
-func (n *nilItem) Release()           {}
-
-func (i *nilItem) Expired() bool {
-	return true
-}
-
-func (i *nilItem) TTL() time.Duration {
-	return time.Minute
-}
-
-func (i *nilItem) Expires() time.Time {
-	return time.Time{}
-}
-
-func (i *nilItem) Extend(duration time.Duration) {
-}
-
-var NilTracked = new(nilItem)
-
-type Item struct {
+type Item[T any] struct {
 	key        string
 	group      string
 	promotions int32
 	refCount   int32
 	expires    int64
 	size       int64
-	value      interface{}
+	value      T
 	element    *list.Element
 }
 
-func newItem(key string, value interface{}, expires int64, track bool) *Item {
+func newItem[T any](key string, value T, expires int64, track bool) *Item[T] {
 	size := int64(1)
-	if sized, ok := value.(Sized); ok {
+
+	// https://github.com/golang/go/issues/49206
+	if sized, ok := (interface{})(value).(Sized); ok {
 		size = sized.Size()
 	}
-	item := &Item{
+	item := &Item[T]{
 		key:        key,
 		value:      value,
 		promotions: 0,
@@ -71,39 +51,39 @@ func newItem(key string, value interface{}, expires int64, track bool) *Item {
 	return item
 }
 
-func (i *Item) shouldPromote(getsPerPromote int32) bool {
+func (i *Item[T]) shouldPromote(getsPerPromote int32) bool {
 	i.promotions += 1
 	return i.promotions == getsPerPromote
 }
 
-func (i *Item) Value() interface{} {
+func (i *Item[T]) Value() T {
 	return i.value
 }
 
-func (i *Item) track() {
+func (i *Item[T]) track() {
 	atomic.AddInt32(&i.refCount, 1)
 }
 
-func (i *Item) Release() {
+func (i *Item[T]) Release() {
 	atomic.AddInt32(&i.refCount, -1)
 }
 
-func (i *Item) Expired() bool {
+func (i *Item[T]) Expired() bool {
 	expires := atomic.LoadInt64(&i.expires)
 	return expires < time.Now().UnixNano()
 }
 
-func (i *Item) TTL() time.Duration {
+func (i *Item[T]) TTL() time.Duration {
 	expires := atomic.LoadInt64(&i.expires)
 	return time.Nanosecond * time.Duration(expires-time.Now().UnixNano())
 }
 
-func (i *Item) Expires() time.Time {
+func (i *Item[T]) Expires() time.Time {
 	expires := atomic.LoadInt64(&i.expires)
 	return time.Unix(0, expires)
 }
 
-func (i *Item) Extend(duration time.Duration) {
+func (i *Item[T]) Extend(duration time.Duration) {
 	atomic.StoreInt64(&i.expires, time.Now().Add(duration).UnixNano())
 }
 
@@ -113,6 +93,6 @@ func (i *Item) Extend(duration time.Duration) {
 // purposes, and because otherwise including an Item in a call to fmt.Printf or
 // fmt.Sprintf expression could cause fields of the Item to be read in a non-thread-safe
 // way.
-func (i *Item) String() string {
+func (i *Item[T]) String() string {
 	return fmt.Sprintf("Item(%v)", i.value)
 }
diff --git a/item_test.go b/item_test.go
index 9311c9b..c513763 100644
--- a/item_test.go
+++ b/item_test.go
@@ -15,35 +15,35 @@ func Test_Item(t *testing.T) {
 }
 
 func (_ *ItemTests) Promotability() {
-	item := &Item{promotions: 4}
+	item := &Item[int]{promotions: 4}
 	Expect(item.shouldPromote(5)).To.Equal(true)
 	Expect(item.shouldPromote(5)).To.Equal(false)
 }
 
 func (_ *ItemTests) Expired() {
 	now := time.Now().UnixNano()
-	item1 := &Item{expires: now + (10 * int64(time.Millisecond))}
-	item2 := &Item{expires: now - (10 * int64(time.Millisecond))}
+	item1 := &Item[int]{expires: now + (10 * int64(time.Millisecond))}
+	item2 := &Item[int]{expires: now - (10 * int64(time.Millisecond))}
 	Expect(item1.Expired()).To.Equal(false)
 	Expect(item2.Expired()).To.Equal(true)
 }
 
 func (_ *ItemTests) TTL() {
 	now := time.Now().UnixNano()
-	item1 := &Item{expires: now + int64(time.Second)}
-	item2 := &Item{expires: now - int64(time.Second)}
+	item1 := &Item[int]{expires: now + int64(time.Second)}
+	item2 := &Item[int]{expires: now - int64(time.Second)}
 	Expect(int(math.Ceil(item1.TTL().Seconds()))).To.Equal(1)
 	Expect(int(math.Ceil(item2.TTL().Seconds()))).To.Equal(-1)
 }
 
 func (_ *ItemTests) Expires() {
 	now := time.Now().UnixNano()
-	item := &Item{expires: now + (10)}
+	item := &Item[int]{expires: now + (10)}
 	Expect(item.Expires().UnixNano()).To.Equal(now + 10)
 }
 
 func (_ *ItemTests) Extend() {
-	item := &Item{expires: time.Now().UnixNano() + 10}
+	item := &Item[int]{expires: time.Now().UnixNano() + 10}
 	item.Extend(time.Minute * 2)
 	Expect(item.Expires().Unix()).To.Equal(time.Now().Unix() + 120)
 }
diff --git a/layeredbucket.go b/layeredbucket.go
index 46e704d..0d8aa8e 100644
--- a/layeredbucket.go
+++ b/layeredbucket.go
@@ -5,12 +5,12 @@ import (
 	"time"
 )
 
-type layeredBucket struct {
+type layeredBucket[T any] struct {
 	sync.RWMutex
-	buckets map[string]*bucket
+	buckets map[string]*bucket[T]
 }
 
-func (b *layeredBucket) itemCount() int {
+func (b *layeredBucket[T]) itemCount() int {
 	count := 0
 	b.RLock()
 	defer b.RUnlock()
@@ -20,7 +20,7 @@ func (b *layeredBucket) itemCount() int {
 	return count
 }
 
-func (b *layeredBucket) get(primary, secondary string) *Item {
+func (b *layeredBucket[T]) get(primary, secondary string) *Item[T] {
 	bucket := b.getSecondaryBucket(primary)
 	if bucket == nil {
 		return nil
@@ -28,7 +28,7 @@ func (b *layeredBucket) get(primary, secondary string) *Item {
 	return bucket.get(secondary)
 }
 
-func (b *layeredBucket) getSecondaryBucket(primary string) *bucket {
+func (b *layeredBucket[T]) getSecondaryBucket(primary string) *bucket[T] {
 	b.RLock()
 	bucket, exists := b.buckets[primary]
 	b.RUnlock()
@@ -38,11 +38,11 @@ func (b *layeredBucket) getSecondaryBucket(primary string) *bucket {
 	return bucket
 }
 
-func (b *layeredBucket) set(primary, secondary string, value interface{}, duration time.Duration, track bool) (*Item, *Item) {
+func (b *layeredBucket[T]) set(primary, secondary string, value T, duration time.Duration, track bool) (*Item[T], *Item[T]) {
 	b.Lock()
 	bkt, exists := b.buckets[primary]
 	if exists == false {
-		bkt = &bucket{lookup: make(map[string]*Item)}
+		bkt = &bucket[T]{lookup: make(map[string]*Item[T])}
 		b.buckets[primary] = bkt
 	}
 	b.Unlock()
@@ -51,7 +51,7 @@ func (b *layeredBucket) set(primary, secondary string, value interface{}, durati
 	return item, existing
 }
 
-func (b *layeredBucket) delete(primary, secondary string) *Item {
+func (b *layeredBucket[T]) delete(primary, secondary string) *Item[T] {
 	b.RLock()
 	bucket, exists := b.buckets[primary]
 	b.RUnlock()
@@ -61,7 +61,7 @@ func (b *layeredBucket) delete(primary, secondary string) *Item {
 	return bucket.delete(secondary)
 }
 
-func (b *layeredBucket) deletePrefix(primary, prefix string, deletables chan *Item) int {
+func (b *layeredBucket[T]) deletePrefix(primary, prefix string, deletables chan *Item[T]) int {
 	b.RLock()
 	bucket, exists := b.buckets[primary]
 	b.RUnlock()
@@ -71,7 +71,7 @@ func (b *layeredBucket) deletePrefix(primary, prefix string, deletables chan *It
 	return bucket.deletePrefix(prefix, deletables)
 }
 
-func (b *layeredBucket) deleteFunc(primary string, matches func(key string, item *Item) bool, deletables chan *Item) int {
+func (b *layeredBucket[T]) deleteFunc(primary string, matches func(key string, item *Item[T]) bool, deletables chan *Item[T]) int {
 	b.RLock()
 	bucket, exists := b.buckets[primary]
 	b.RUnlock()
@@ -81,7 +81,7 @@ func (b *layeredBucket) deleteFunc(primary string, matches func(key string, item
 	return bucket.deleteFunc(matches, deletables)
 }
 
-func (b *layeredBucket) deleteAll(primary string, deletables chan *Item) bool {
+func (b *layeredBucket[T]) deleteAll(primary string, deletables chan *Item[T]) bool {
 	b.RLock()
 	bucket, exists := b.buckets[primary]
 	b.RUnlock()
@@ -102,7 +102,7 @@ func (b *layeredBucket) deleteAll(primary string, deletables chan *Item) bool {
 	return true
 }
 
-func (b *layeredBucket) forEachFunc(primary string, matches func(key string, item *Item) bool) {
+func (b *layeredBucket[T]) forEachFunc(primary string, matches func(key string, item *Item[T]) bool) {
 	b.RLock()
 	bucket, exists := b.buckets[primary]
 	b.RUnlock()
@@ -111,11 +111,11 @@ func (b *layeredBucket) forEachFunc(primary string, matches func(key string, ite
 	}
 }
 
-func (b *layeredBucket) clear() {
+func (b *layeredBucket[T]) clear() {
 	b.Lock()
 	defer b.Unlock()
 	for _, bucket := range b.buckets {
 		bucket.clear()
 	}
-	b.buckets = make(map[string]*bucket)
+	b.buckets = make(map[string]*bucket[T])
 }
diff --git a/layeredcache.go b/layeredcache.go
index 51b1f21..28957e7 100644
--- a/layeredcache.go
+++ b/layeredcache.go
@@ -8,14 +8,14 @@ import (
 	"time"
 )
 
-type LayeredCache struct {
-	*Configuration
+type LayeredCache[T any] struct {
+	*Configuration[T]
 	list        *list.List
-	buckets     []*layeredBucket
+	buckets     []*layeredBucket[T]
 	bucketMask  uint32
 	size        int64
-	deletables  chan *Item
-	promotables chan *Item
+	deletables  chan *Item[T]
+	promotables chan *Item[T]
 	control     chan interface{}
 }
 
@@ -32,25 +32,25 @@ type LayeredCache struct {
 // secondary key 2 = ".xml"
 
 // See ccache.Configure() for creating a configuration
-func Layered(config *Configuration) *LayeredCache {
-	c := &LayeredCache{
+func Layered[T any](config *Configuration[T]) *LayeredCache[T] {
+	c := &LayeredCache[T]{
 		list:          list.New(),
 		Configuration: config,
 		bucketMask:    uint32(config.buckets) - 1,
-		buckets:       make([]*layeredBucket, config.buckets),
-		deletables:    make(chan *Item, config.deleteBuffer),
+		buckets:       make([]*layeredBucket[T], config.buckets),
+		deletables:    make(chan *Item[T], config.deleteBuffer),
 		control:       make(chan interface{}),
 	}
 	for i := 0; i < int(config.buckets); i++ {
-		c.buckets[i] = &layeredBucket{
-			buckets: make(map[string]*bucket),
+		c.buckets[i] = &layeredBucket[T]{
+			buckets: make(map[string]*bucket[T]),
 		}
 	}
 	c.restart()
 	return c
 }
 
-func (c *LayeredCache) ItemCount() int {
+func (c *LayeredCache[T]) ItemCount() int {
 	count := 0
 	for _, b := range c.buckets {
 		count += b.itemCount()
@@ -62,7 +62,7 @@ func (c *LayeredCache) ItemCount() int {
 // This can return an expired item. Use item.Expired() to see if the item
 // is expired and item.TTL() to see how long until the item expires (which
 // will be negative for an already expired item).
-func (c *LayeredCache) Get(primary, secondary string) *Item {
+func (c *LayeredCache[T]) Get(primary, secondary string) *Item[T] {
 	item := c.bucket(primary).get(primary, secondary)
 	if item == nil {
 		return nil
@@ -76,23 +76,23 @@ func (c *LayeredCache) Get(primary, secondary string) *Item {
 	return item
 }
 
-func (c *LayeredCache) ForEachFunc(primary string, matches func(key string, item *Item) bool) {
+func (c *LayeredCache[T]) ForEachFunc(primary string, matches func(key string, item *Item[T]) bool) {
 	c.bucket(primary).forEachFunc(primary, matches)
 }
 
 // Get the secondary cache for a given primary key. This operation will
 // never return nil. In the case where the primary key does not exist, a
 // new, underlying, empty bucket will be created and returned.
-func (c *LayeredCache) GetOrCreateSecondaryCache(primary string) *SecondaryCache {
+func (c *LayeredCache[T]) GetOrCreateSecondaryCache(primary string) *SecondaryCache[T] {
 	primaryBkt := c.bucket(primary)
 	bkt := primaryBkt.getSecondaryBucket(primary)
 	primaryBkt.Lock()
 	if bkt == nil {
-		bkt = &bucket{lookup: make(map[string]*Item)}
+		bkt = &bucket[T]{lookup: make(map[string]*Item[T])}
 		primaryBkt.buckets[primary] = bkt
 	}
 	primaryBkt.Unlock()
-	return &SecondaryCache{
+	return &SecondaryCache[T]{
 		bucket: bkt,
 		pCache: c,
 	}
@@ -100,29 +100,29 @@ func (c *LayeredCache) GetOrCreateSecondaryCache(primary string) *SecondaryCache
 
 // Used when the cache was created with the Track() configuration option.
 // Avoid otherwise
-func (c *LayeredCache) TrackingGet(primary, secondary string) TrackedItem {
+func (c *LayeredCache[T]) TrackingGet(primary, secondary string) TrackedItem[T] {
 	item := c.Get(primary, secondary)
 	if item == nil {
-		return NilTracked
+		return nil
 	}
 	item.track()
 	return item
 }
 
 // Set the value in the cache for the specified duration
-func (c *LayeredCache) TrackingSet(primary, secondary string, value interface{}, duration time.Duration) TrackedItem {
+func (c *LayeredCache[T]) TrackingSet(primary, secondary string, value T, duration time.Duration) TrackedItem[T] {
 	return c.set(primary, secondary, value, duration, true)
 }
 
 // Set the value in the cache for the specified duration
-func (c *LayeredCache) Set(primary, secondary string, value interface{}, duration time.Duration) {
+func (c *LayeredCache[T]) Set(primary, secondary string, value T, duration time.Duration) {
 	c.set(primary, secondary, value, duration, false)
 }
 
 // Replace the value if it exists, does not set if it doesn't.
 // Returns true if the item existed an was replaced, false otherwise.
 // Replace does not reset item's TTL nor does it alter its position in the LRU
-func (c *LayeredCache) Replace(primary, secondary string, value interface{}) bool {
+func (c *LayeredCache[T]) Replace(primary, secondary string, value T) bool {
 	item := c.bucket(primary).get(primary, secondary)
 	if item == nil {
 		return false
@@ -137,7 +137,7 @@ func (c *LayeredCache) Replace(primary, secondary string, value interface{}) boo
 // Note that Fetch merely calls the public Get and Set functions. If you want
 // a different Fetch behavior, such as thundering herd protection or returning
 // expired items, implement it in your application.
-func (c *LayeredCache) Fetch(primary, secondary string, duration time.Duration, fetch func() (interface{}, error)) (*Item, error) {
+func (c *LayeredCache[T]) Fetch(primary, secondary string, duration time.Duration, fetch func() (T, error)) (*Item[T], error) {
 	item := c.Get(primary, secondary)
 	if item != nil {
 		return item, nil
@@ -150,7 +150,7 @@ func (c *LayeredCache) Fetch(primary, secondary string, duration time.Duration,
 }
 
 // Remove the item from the cache, return true if the item was present, false otherwise.
-func (c *LayeredCache) Delete(primary, secondary string) bool {
+func (c *LayeredCache[T]) Delete(primary, secondary string) bool {
 	item := c.bucket(primary).delete(primary, secondary)
 	if item != nil {
 		c.deletables <- item
@@ -160,47 +160,47 @@ func (c *LayeredCache) Delete(primary, secondary string) bool {
 }
 
 // Deletes all items that share the same primary key
-func (c *LayeredCache) DeleteAll(primary string) bool {
+func (c *LayeredCache[T]) DeleteAll(primary string) bool {
 	return c.bucket(primary).deleteAll(primary, c.deletables)
 }
 
 // Deletes all items that share the same primary key and prefix.
-func (c *LayeredCache) DeletePrefix(primary, prefix string) int {
+func (c *LayeredCache[T]) DeletePrefix(primary, prefix string) int {
 	return c.bucket(primary).deletePrefix(primary, prefix, c.deletables)
 }
 
 // Deletes all items that share the same primary key and where the matches func evaluates to true.
-func (c *LayeredCache) DeleteFunc(primary string, matches func(key string, item *Item) bool) int {
+func (c *LayeredCache[T]) DeleteFunc(primary string, matches func(key string, item *Item[T]) bool) int {
 	return c.bucket(primary).deleteFunc(primary, matches, c.deletables)
 }
 
 // Clears the cache
-func (c *LayeredCache) Clear() {
+func (c *LayeredCache[T]) Clear() {
 	done := make(chan struct{})
 	c.control <- clear{done: done}
 	<-done
 }
 
-func (c *LayeredCache) Stop() {
+func (c *LayeredCache[T]) Stop() {
 	close(c.promotables)
 	<-c.control
 }
 
 // Gets the number of items removed from the cache due to memory pressure since
 // the last time GetDropped was called
-func (c *LayeredCache) GetDropped() int {
+func (c *LayeredCache[T]) GetDropped() int {
 	return doGetDropped(c.control)
 }
 
 // SyncUpdates waits until the cache has finished asynchronous state updates for any operations
 // that were done by the current goroutine up to now. See Cache.SyncUpdates for details.
-func (c *LayeredCache) SyncUpdates() {
+func (c *LayeredCache[T]) SyncUpdates() {
 	doSyncUpdates(c.control)
 }
 
 // Sets a new max size. That can result in a GC being run if the new maxium size
 // is smaller than the cached size
-func (c *LayeredCache) SetMaxSize(size int64) {
+func (c *LayeredCache[T]) SetMaxSize(size int64) {
 	done := make(chan struct{})
 	c.control <- setMaxSize{size: size, done: done}
 	<-done
@@ -209,7 +209,7 @@ func (c *LayeredCache) SetMaxSize(size int64) {
 // Forces GC. There should be no reason to call this function, except from tests
 // which require synchronous GC.
 // This is a control command.
-func (c *LayeredCache) GC() {
+func (c *LayeredCache[T]) GC() {
 	done := make(chan struct{})
 	c.control <- gc{done: done}
 	<-done
@@ -219,19 +219,19 @@ func (c *LayeredCache) GC() {
 // by the worker goroutine. It's meant to be called periodically for metrics, or
 // from tests.
 // This is a control command.
-func (c *LayeredCache) GetSize() int64 {
+func (c *LayeredCache[T]) GetSize() int64 {
 	res := make(chan int64)
 	c.control <- getSize{res}
 	return <-res
 }
 
-func (c *LayeredCache) restart() {
-	c.promotables = make(chan *Item, c.promoteBuffer)
+func (c *LayeredCache[T]) restart() {
+	c.promotables = make(chan *Item[T], c.promoteBuffer)
 	c.control = make(chan interface{})
 	go c.worker()
 }
 
-func (c *LayeredCache) set(primary, secondary string, value interface{}, duration time.Duration, track bool) *Item {
+func (c *LayeredCache[T]) set(primary, secondary string, value T, duration time.Duration, track bool) *Item[T] {
 	item, existing := c.bucket(primary).set(primary, secondary, value, duration, track)
 	if existing != nil {
 		c.deletables <- existing
@@ -240,25 +240,25 @@ func (c *LayeredCache) set(primary, secondary string, value interface{}, duratio
 	return item
 }
 
-func (c *LayeredCache) bucket(key string) *layeredBucket {
+func (c *LayeredCache[T]) bucket(key string) *layeredBucket[T] {
 	h := fnv.New32a()
 	h.Write([]byte(key))
 	return c.buckets[h.Sum32()&c.bucketMask]
 }
 
-func (c *LayeredCache) promote(item *Item) {
+func (c *LayeredCache[T]) promote(item *Item[T]) {
 	c.promotables <- item
 }
 
-func (c *LayeredCache) worker() {
+func (c *LayeredCache[T]) worker() {
 	defer close(c.control)
 	dropped := 0
-	promoteItem := func(item *Item) {
+	promoteItem := func(item *Item[T]) {
 		if c.doPromote(item) && c.size > c.maxSize {
 			dropped += c.gc()
 		}
 	}
-	deleteItem := func(item *Item) {
+	deleteItem := func(item *Item[T]) {
 		if item.element == nil {
 			atomic.StoreInt32(&item.promotions, -2)
 		} else {
@@ -310,7 +310,7 @@ func (c *LayeredCache) worker() {
 	}
 }
 
-func (c *LayeredCache) doPromote(item *Item) bool {
+func (c *LayeredCache[T]) doPromote(item *Item[T]) bool {
 	// deleted before it ever got promoted
 	if atomic.LoadInt32(&item.promotions) == -2 {
 		return false
@@ -327,7 +327,7 @@ func (c *LayeredCache) doPromote(item *Item) bool {
 	return true
 }
 
-func (c *LayeredCache) gc() int {
+func (c *LayeredCache[T]) gc() int {
 	element := c.list.Back()
 	dropped := 0
 	itemsToPrune := int64(c.itemsToPrune)
@@ -341,7 +341,7 @@ func (c *LayeredCache) gc() int {
 			return dropped
 		}
 		prev := element.Prev()
-		item := element.Value.(*Item)
+		item := element.Value.(*Item[T])
 		if c.tracking == false || atomic.LoadInt32(&item.refCount) == 0 {
 			c.bucket(item.group).delete(item.group, item.key)
 			c.size -= item.size
diff --git a/layeredcache_test.go b/layeredcache_test.go
index 2fa12fa..2d5af0f 100644
--- a/layeredcache_test.go
+++ b/layeredcache_test.go
@@ -17,13 +17,13 @@ func Test_LayeredCache(t *testing.T) {
 }
 
 func (_ *LayeredCacheTests) GetsANonExistantValue() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	Expect(cache.Get("spice", "flow")).To.Equal(nil)
 	Expect(cache.ItemCount()).To.Equal(0)
 }
 
 func (_ *LayeredCacheTests) SetANewValue() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "a value", time.Minute)
 	Expect(cache.Get("spice", "flow").Value()).To.Equal("a value")
 	Expect(cache.Get("spice", "stop")).To.Equal(nil)
@@ -31,7 +31,7 @@ func (_ *LayeredCacheTests) SetANewValue() {
 }
 
 func (_ *LayeredCacheTests) SetsMultipleValueWithinTheSameLayer() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "value-a", time.Minute)
 	cache.Set("spice", "must", "value-b", time.Minute)
 	cache.Set("leto", "sister", "ghanima", time.Minute)
@@ -46,22 +46,22 @@ func (_ *LayeredCacheTests) SetsMultipleValueWithinTheSameLayer() {
 }
 
 func (_ *LayeredCacheTests) ReplaceDoesNothingIfKeyDoesNotExist() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	Expect(cache.Replace("spice", "flow", "value-a")).To.Equal(false)
 	Expect(cache.Get("spice", "flow")).To.Equal(nil)
 }
 
 func (_ *LayeredCacheTests) ReplaceUpdatesTheValue() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "value-a", time.Minute)
 	Expect(cache.Replace("spice", "flow", "value-b")).To.Equal(true)
-	Expect(cache.Get("spice", "flow").Value().(string)).To.Equal("value-b")
+	Expect(cache.Get("spice", "flow").Value()).To.Equal("value-b")
 	Expect(cache.ItemCount()).To.Equal(1)
 	//not sure how to test that the TTL hasn't changed sort of a sleep..
 }
 
 func (_ *LayeredCacheTests) DeletesAValue() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "value-a", time.Minute)
 	cache.Set("spice", "must", "value-b", time.Minute)
 	cache.Set("leto", "sister", "ghanima", time.Minute)
@@ -74,7 +74,7 @@ func (_ *LayeredCacheTests) DeletesAValue() {
 }
 
 func (_ *LayeredCacheTests) DeletesAPrefix() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	Expect(cache.ItemCount()).To.Equal(0)
 
 	cache.Set("spice", "aaa", "1", time.Minute)
@@ -98,7 +98,7 @@ func (_ *LayeredCacheTests) DeletesAPrefix() {
 }
 
 func (_ *LayeredCacheTests) DeletesAFunc() {
-	cache := newLayered()
+	cache := newLayered[int]()
 	Expect(cache.ItemCount()).To.Equal(0)
 
 	cache.Set("spice", "a", 1, time.Minute)
@@ -109,17 +109,17 @@ func (_ *LayeredCacheTests) DeletesAFunc() {
 	cache.Set("spice", "f", 6, time.Minute)
 	Expect(cache.ItemCount()).To.Equal(6)
 
-	Expect(cache.DeleteFunc("spice", func(key string, item *Item) bool {
+	Expect(cache.DeleteFunc("spice", func(key string, item *Item[int]) bool {
 		return false
 	})).To.Equal(0)
 	Expect(cache.ItemCount()).To.Equal(6)
 
-	Expect(cache.DeleteFunc("spice", func(key string, item *Item) bool {
-		return item.Value().(int) < 4
+	Expect(cache.DeleteFunc("spice", func(key string, item *Item[int]) bool {
+		return item.Value() < 4
 	})).To.Equal(2)
 	Expect(cache.ItemCount()).To.Equal(4)
 
-	Expect(cache.DeleteFunc("spice", func(key string, item *Item) bool {
+	Expect(cache.DeleteFunc("spice", func(key string, item *Item[int]) bool {
 		return key == "d"
 	})).To.Equal(1)
 	Expect(cache.ItemCount()).To.Equal(3)
@@ -128,13 +128,13 @@ func (_ *LayeredCacheTests) DeletesAFunc() {
 
 func (_ *LayeredCacheTests) OnDeleteCallbackCalled() {
 	onDeleteFnCalled := int32(0)
-	onDeleteFn := func(item *Item) {
+	onDeleteFn := func(item *Item[string]) {
 		if item.group == "spice" && item.key == "flow" {
 			atomic.AddInt32(&onDeleteFnCalled, 1)
 		}
 	}
 
-	cache := Layered(Configure().OnDelete(onDeleteFn))
+	cache := Layered[string](Configure[string]().OnDelete(onDeleteFn))
 	cache.Set("spice", "flow", "value-a", time.Minute)
 	cache.Set("spice", "must", "value-b", time.Minute)
 	cache.Set("leto", "sister", "ghanima", time.Minute)
@@ -152,7 +152,7 @@ func (_ *LayeredCacheTests) OnDeleteCallbackCalled() {
 }
 
 func (_ *LayeredCacheTests) DeletesALayer() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "value-a", time.Minute)
 	cache.Set("spice", "must", "value-b", time.Minute)
 	cache.Set("leto", "sister", "ghanima", time.Minute)
@@ -164,7 +164,7 @@ func (_ *LayeredCacheTests) DeletesALayer() {
 }
 
 func (_ LayeredCacheTests) GCsTheOldestItems() {
-	cache := Layered(Configure().ItemsToPrune(10))
+	cache := Layered[int](Configure[int]().ItemsToPrune(10))
 	cache.Set("xx", "a", 23, time.Minute)
 	for i := 0; i < 500; i++ {
 		cache.Set(strconv.Itoa(i), "a", i, time.Minute)
@@ -181,7 +181,7 @@ func (_ LayeredCacheTests) GCsTheOldestItems() {
 }
 
 func (_ LayeredCacheTests) PromotedItemsDontGetPruned() {
-	cache := Layered(Configure().ItemsToPrune(10).GetsPerPromote(1))
+	cache := Layered[int](Configure[int]().ItemsToPrune(10).GetsPerPromote(1))
 	for i := 0; i < 500; i++ {
 		cache.Set(strconv.Itoa(i), "a", i, time.Minute)
 	}
@@ -195,7 +195,7 @@ func (_ LayeredCacheTests) PromotedItemsDontGetPruned() {
 }
 
 func (_ LayeredCacheTests) TrackerDoesNotCleanupHeldInstance() {
-	cache := Layered(Configure().ItemsToPrune(10).Track())
+	cache := Layered[int](Configure[int]().ItemsToPrune(10).Track())
 	item0 := cache.TrackingSet("0", "a", 0, time.Minute)
 	for i := 1; i < 11; i++ {
 		cache.Set(strconv.Itoa(i), "a", i, time.Minute)
@@ -213,7 +213,7 @@ func (_ LayeredCacheTests) TrackerDoesNotCleanupHeldInstance() {
 }
 
 func (_ LayeredCacheTests) RemovesOldestItemWhenFull() {
-	cache := Layered(Configure().MaxSize(5).ItemsToPrune(1))
+	cache := Layered[int](Configure[int]().MaxSize(5).ItemsToPrune(1))
 	cache.Set("xx", "a", 23, time.Minute)
 	for i := 0; i < 7; i++ {
 		cache.Set(strconv.Itoa(i), "a", i, time.Minute)
@@ -231,7 +231,7 @@ func (_ LayeredCacheTests) RemovesOldestItemWhenFull() {
 }
 
 func (_ LayeredCacheTests) ResizeOnTheFly() {
-	cache := Layered(Configure().MaxSize(9).ItemsToPrune(1))
+	cache := Layered[int](Configure[int]().MaxSize(9).ItemsToPrune(1))
 	for i := 0; i < 5; i++ {
 		cache.Set(strconv.Itoa(i), "a", i, time.Minute)
 	}
@@ -265,7 +265,7 @@ func (_ LayeredCacheTests) ResizeOnTheFly() {
 }
 
 func (_ LayeredCacheTests) RemovesOldestItemWhenFullBySizer() {
-	cache := Layered(Configure().MaxSize(9).ItemsToPrune(2))
+	cache := Layered[*SizedItem](Configure[*SizedItem]().MaxSize(9).ItemsToPrune(2))
 	for i := 0; i < 7; i++ {
 		cache.Set("pri", strconv.Itoa(i), &SizedItem{i, 2}, time.Minute)
 	}
@@ -274,11 +274,11 @@ func (_ LayeredCacheTests) RemovesOldestItemWhenFullBySizer() {
 	Expect(cache.Get("pri", "1")).To.Equal(nil)
 	Expect(cache.Get("pri", "2")).To.Equal(nil)
 	Expect(cache.Get("pri", "3")).To.Equal(nil)
-	Expect(cache.Get("pri", "4").Value().(*SizedItem).id).To.Equal(4)
+	Expect(cache.Get("pri", "4").Value().id).To.Equal(4)
 }
 
 func (_ LayeredCacheTests) SetUpdatesSizeOnDelta() {
-	cache := Layered(Configure())
+	cache := Layered[*SizedItem](Configure[*SizedItem]())
 	cache.Set("pri", "a", &SizedItem{0, 2}, time.Minute)
 	cache.Set("pri", "b", &SizedItem{0, 3}, time.Minute)
 	cache.SyncUpdates()
@@ -299,7 +299,7 @@ func (_ LayeredCacheTests) SetUpdatesSizeOnDelta() {
 }
 
 func (_ LayeredCacheTests) ReplaceDoesNotchangeSizeIfNotSet() {
-	cache := Layered(Configure())
+	cache := Layered[*SizedItem](Configure[*SizedItem]())
 	cache.Set("pri", "1", &SizedItem{1, 2}, time.Minute)
 	cache.Set("pri", "2", &SizedItem{1, 2}, time.Minute)
 	cache.Set("pri", "3", &SizedItem{1, 2}, time.Minute)
@@ -309,7 +309,7 @@ func (_ LayeredCacheTests) ReplaceDoesNotchangeSizeIfNotSet() {
 }
 
 func (_ LayeredCacheTests) ReplaceChangesSize() {
-	cache := Layered(Configure())
+	cache := Layered[*SizedItem](Configure[*SizedItem]())
 	cache.Set("pri", "1", &SizedItem{1, 2}, time.Minute)
 	cache.Set("pri", "2", &SizedItem{1, 2}, time.Minute)
 
@@ -327,43 +327,43 @@ func (_ LayeredCacheTests) ReplaceChangesSize() {
 }
 
 func (_ LayeredCacheTests) EachFunc() {
-	cache := Layered(Configure().MaxSize(3).ItemsToPrune(1))
-	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{})
+	cache := Layered[int](Configure[int]().MaxSize(3).ItemsToPrune(1))
+	Expect(forEachKeysLayered[int](cache, "1")).To.Equal([]string{})
 
 	cache.Set("1", "a", 1, time.Minute)
-	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{"a"})
+	Expect(forEachKeysLayered[int](cache, "1")).To.Equal([]string{"a"})
 
 	cache.Set("1", "b", 2, time.Minute)
 	cache.SyncUpdates()
-	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{"a", "b"})
+	Expect(forEachKeysLayered[int](cache, "1")).To.Equal([]string{"a", "b"})
 
 	cache.Set("1", "c", 3, time.Minute)
 	cache.SyncUpdates()
-	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{"a", "b", "c"})
+	Expect(forEachKeysLayered[int](cache, "1")).To.Equal([]string{"a", "b", "c"})
 
 	cache.Set("1", "d", 4, time.Minute)
 	cache.SyncUpdates()
-	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{"b", "c", "d"})
+	Expect(forEachKeysLayered[int](cache, "1")).To.Equal([]string{"b", "c", "d"})
 
 	// iteration is non-deterministic, all we know for sure is "stop" should not be in there
 	cache.Set("1", "stop", 5, time.Minute)
 	cache.SyncUpdates()
-	Expect(forEachKeysLayered(cache, "1")).Not.To.Contain("stop")
+	Expect(forEachKeysLayered[int](cache, "1")).Not.To.Contain("stop")
 
 	cache.Set("1", "e", 6, time.Minute)
 	cache.SyncUpdates()
-	Expect(forEachKeysLayered(cache, "1")).Not.To.Contain("stop")
+	Expect(forEachKeysLayered[int](cache, "1")).Not.To.Contain("stop")
 }
 
-func newLayered() *LayeredCache {
-	c := Layered(Configure())
+func newLayered[T any]() *LayeredCache[T] {
+	c := Layered[T](Configure[T]())
 	c.Clear()
 	return c
 }
 
-func forEachKeysLayered(cache *LayeredCache, primary string) []string {
+func forEachKeysLayered[T any](cache *LayeredCache[T], primary string) []string {
 	keys := make([]string, 0, 10)
-	cache.ForEachFunc(primary, func(key string, i *Item) bool {
+	cache.ForEachFunc(primary, func(key string, i *Item[T]) bool {
 		if key == "stop" {
 			return false
 		}
diff --git a/secondarycache.go b/secondarycache.go
index cd322c2..0f62df3 100644
--- a/secondarycache.go
+++ b/secondarycache.go
@@ -2,20 +2,20 @@ package ccache
 
 import "time"
 
-type SecondaryCache struct {
-	bucket *bucket
-	pCache *LayeredCache
+type SecondaryCache[T any] struct {
+	bucket *bucket[T]
+	pCache *LayeredCache[T]
 }
 
 // Get the secondary key.
 // The semantics are the same as for LayeredCache.Get
-func (s *SecondaryCache) Get(secondary string) *Item {
+func (s *SecondaryCache[T]) Get(secondary string) *Item[T] {
 	return s.bucket.get(secondary)
 }
 
 // Set the secondary key to a value.
 // The semantics are the same as for LayeredCache.Set
-func (s *SecondaryCache) Set(secondary string, value interface{}, duration time.Duration) *Item {
+func (s *SecondaryCache[T]) Set(secondary string, value T, duration time.Duration) *Item[T] {
 	item, existing := s.bucket.set(secondary, value, duration, false)
 	if existing != nil {
 		s.pCache.deletables <- existing
@@ -26,7 +26,7 @@ func (s *SecondaryCache) Set(secondary string, value interface{}, duration time.
 
 // Fetch or set a secondary key.
 // The semantics are the same as for LayeredCache.Fetch
-func (s *SecondaryCache) Fetch(secondary string, duration time.Duration, fetch func() (interface{}, error)) (*Item, error) {
+func (s *SecondaryCache[T]) Fetch(secondary string, duration time.Duration, fetch func() (T, error)) (*Item[T], error) {
 	item := s.Get(secondary)
 	if item != nil {
 		return item, nil
@@ -40,7 +40,7 @@ func (s *SecondaryCache) Fetch(secondary string, duration time.Duration, fetch f
 
 // Delete a secondary key.
 // The semantics are the same as for LayeredCache.Delete
-func (s *SecondaryCache) Delete(secondary string) bool {
+func (s *SecondaryCache[T]) Delete(secondary string) bool {
 	item := s.bucket.delete(secondary)
 	if item != nil {
 		s.pCache.deletables <- item
@@ -51,7 +51,7 @@ func (s *SecondaryCache) Delete(secondary string) bool {
 
 // Replace a secondary key.
 // The semantics are the same as for LayeredCache.Replace
-func (s *SecondaryCache) Replace(secondary string, value interface{}) bool {
+func (s *SecondaryCache[T]) Replace(secondary string, value T) bool {
 	item := s.Get(secondary)
 	if item == nil {
 		return false
@@ -62,10 +62,10 @@ func (s *SecondaryCache) Replace(secondary string, value interface{}) bool {
 
 // Track a secondary key.
 // The semantics are the same as for LayeredCache.TrackingGet
-func (c *SecondaryCache) TrackingGet(secondary string) TrackedItem {
+func (c *SecondaryCache[T]) TrackingGet(secondary string) TrackedItem[T] {
 	item := c.Get(secondary)
 	if item == nil {
-		return NilTracked
+		return nil
 	}
 	item.track()
 	return item
diff --git a/secondarycache_test.go b/secondarycache_test.go
index e729415..b767635 100644
--- a/secondarycache_test.go
+++ b/secondarycache_test.go
@@ -15,12 +15,12 @@ func Test_SecondaryCache(t *testing.T) {
 }
 
 func (_ SecondaryCacheTests) GetsANonExistantValue() {
-	cache := newLayered().GetOrCreateSecondaryCache("foo")
+	cache := newLayered[string]().GetOrCreateSecondaryCache("foo")
 	Expect(cache).Not.To.Equal(nil)
 }
 
 func (_ SecondaryCacheTests) SetANewValue() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "a value", time.Minute)
 	sCache := cache.GetOrCreateSecondaryCache("spice")
 	Expect(sCache.Get("flow").Value()).To.Equal("a value")
@@ -28,7 +28,7 @@ func (_ SecondaryCacheTests) SetANewValue() {
 }
 
 func (_ SecondaryCacheTests) ValueCanBeSeenInBothCaches1() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "a value", time.Minute)
 	sCache := cache.GetOrCreateSecondaryCache("spice")
 	sCache.Set("orinoco", "another value", time.Minute)
@@ -37,7 +37,7 @@ func (_ SecondaryCacheTests) ValueCanBeSeenInBothCaches1() {
 }
 
 func (_ SecondaryCacheTests) ValueCanBeSeenInBothCaches2() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	sCache := cache.GetOrCreateSecondaryCache("spice")
 	sCache.Set("flow", "a value", time.Minute)
 	Expect(sCache.Get("flow").Value()).To.Equal("a value")
@@ -45,7 +45,7 @@ func (_ SecondaryCacheTests) ValueCanBeSeenInBothCaches2() {
 }
 
 func (_ SecondaryCacheTests) DeletesAreReflectedInBothCaches() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "a value", time.Minute)
 	cache.Set("spice", "sister", "ghanima", time.Minute)
 	sCache := cache.GetOrCreateSecondaryCache("spice")
@@ -60,37 +60,37 @@ func (_ SecondaryCacheTests) DeletesAreReflectedInBothCaches() {
 }
 
 func (_ SecondaryCacheTests) ReplaceDoesNothingIfKeyDoesNotExist() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	sCache := cache.GetOrCreateSecondaryCache("spice")
 	Expect(sCache.Replace("flow", "value-a")).To.Equal(false)
 	Expect(cache.Get("spice", "flow")).To.Equal(nil)
 }
 
 func (_ SecondaryCacheTests) ReplaceUpdatesTheValue() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "value-a", time.Minute)
 	sCache := cache.GetOrCreateSecondaryCache("spice")
 	Expect(sCache.Replace("flow", "value-b")).To.Equal(true)
-	Expect(cache.Get("spice", "flow").Value().(string)).To.Equal("value-b")
+	Expect(cache.Get("spice", "flow").Value()).To.Equal("value-b")
 }
 
 func (_ SecondaryCacheTests) FetchReturnsAnExistingValue() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	cache.Set("spice", "flow", "value-a", time.Minute)
 	sCache := cache.GetOrCreateSecondaryCache("spice")
-	val, _ := sCache.Fetch("flow", time.Minute, func() (interface{}, error) { return "a fetched value", nil })
-	Expect(val.Value().(string)).To.Equal("value-a")
+	val, _ := sCache.Fetch("flow", time.Minute, func() (string, error) { return "a fetched value", nil })
+	Expect(val.Value()).To.Equal("value-a")
 }
 
 func (_ SecondaryCacheTests) FetchReturnsANewValue() {
-	cache := newLayered()
+	cache := newLayered[string]()
 	sCache := cache.GetOrCreateSecondaryCache("spice")
-	val, _ := sCache.Fetch("flow", time.Minute, func() (interface{}, error) { return "a fetched value", nil })
-	Expect(val.Value().(string)).To.Equal("a fetched value")
+	val, _ := sCache.Fetch("flow", time.Minute, func() (string, error) { return "a fetched value", nil })
+	Expect(val.Value()).To.Equal("a fetched value")
 }
 
 func (_ SecondaryCacheTests) TrackerDoesNotCleanupHeldInstance() {
-	cache := Layered(Configure().ItemsToPrune(10).Track())
+	cache := Layered[int](Configure[int]().ItemsToPrune(10).Track())
 	for i := 0; i < 10; i++ {
 		cache.Set(strconv.Itoa(i), "a", i, time.Minute)
 	}