diff --git a/memcache/memcache.go b/memcache/memcache.go
index cab3a5b0..f1cc8137 100644
--- a/memcache/memcache.go
+++ b/memcache/memcache.go
@@ -98,6 +98,11 @@ func (s *Storage) Clear() error {
 	return s.db.DeleteAll()
 }
 
+// Close the storage
+func (s *Storage) Close() error {
+	return nil
+}
+
 // Acquire item from pool
 func (s *Storage) acquireItem() *mc.Item {
 	return s.items.Get().(*mc.Item)
diff --git a/memory/memory.go b/memory/memory.go
index 86bfe1b2..759c2bcb 100644
--- a/memory/memory.go
+++ b/memory/memory.go
@@ -83,6 +83,11 @@ func (s *Storage) Clear() error {
 	return nil
 }
 
+// Close the storage
+func (s *Storage) Close() error {
+	return nil
+}
+
 func (s *Storage) gc() {
 	for t := range time.NewTicker(s.gcInterval).C {
 		now := t.Unix()
diff --git a/mysql/mysql.go b/mysql/mysql.go
index 45ea29d1..42670f58 100644
--- a/mysql/mysql.go
+++ b/mysql/mysql.go
@@ -76,7 +76,7 @@ func New(config ...Config) *Storage {
 		gcInterval: cfg.GCInterval,
 		db:         db,
 		sqlSelect:  fmt.Sprintf("SELECT data, exp FROM %s WHERE id=?;", cfg.Table),
-		sqlInsert:  fmt.Sprintf("INSERT OR REPLACE INTO %s (id, data, exp) VALUES (?,?,?)", cfg.Table),
+		sqlInsert:  fmt.Sprintf("INSERT INTO %s (id, data, exp) VALUES (?,?,?)", cfg.Table),
 		sqlDelete:  fmt.Sprintf("DELETE FROM %s WHERE id=?", cfg.Table),
 		sqlClear:   fmt.Sprintf("DELETE FROM %s;", cfg.Table),
 		sqlGC:      fmt.Sprintf("DELETE FROM %s WHERE exp <= ?", cfg.Table),
@@ -142,6 +142,11 @@ func (s *Storage) Clear() error {
 	return err
 }
 
+// Close the storage
+func (s *Storage) Close() error {
+	return s.db.Close()
+}
+
 // Garbage collector to delete expired keys
 func (s *Storage) gc() {
 	tick := time.NewTicker(s.gcInterval)
diff --git a/postgres/postgres.go b/postgres/postgres.go
index abbb8d17..8c971d8a 100644
--- a/postgres/postgres.go
+++ b/postgres/postgres.go
@@ -158,6 +158,11 @@ func (s *Storage) Clear() error {
 	return err
 }
 
+// Close the storage
+func (s *Storage) Close() error {
+	return s.db.Close()
+}
+
 // GC deletes all expired entries
 func (s *Storage) gc() {
 	tick := time.NewTicker(s.gcInterval)
diff --git a/redis/redis.go b/redis/redis.go
index 86497adb..81cedaad 100644
--- a/redis/redis.go
+++ b/redis/redis.go
@@ -75,3 +75,8 @@ func (s *Storage) Delete(key string) error {
 func (s *Storage) Clear() error {
 	return s.db.FlushDB(context.Background()).Err()
 }
+
+// Close the storage
+func (s *Storage) Close() error {
+	return s.db.Close()
+}
diff --git a/sqlite3/sqlite3.go b/sqlite3/sqlite3.go
index c31f0162..8422d276 100644
--- a/sqlite3/sqlite3.go
+++ b/sqlite3/sqlite3.go
@@ -141,6 +141,11 @@ func (s *Storage) Clear() error {
 	return err
 }
 
+// Close the storage
+func (s *Storage) Close() error {
+	return s.db.Close()
+}
+
 // GC deletes all expired entries
 func (s *Storage) gc() {
 	tick := time.NewTicker(s.gcInterval)