diff --git a/extract.go b/extract.go
index 57d0561..6108cd8 100644
--- a/extract.go
+++ b/extract.go
@@ -115,6 +115,7 @@ func extractField(value *reflect.Value, field *reflect.StructField, m *structCon
 			switch tag {
 			case "id":
 				f.IsID = true
+				f.Index = tagUniqueIdx
 			case tagUniqueIdx, tagIdx:
 				f.Index = tag
 			case tagInline:
@@ -163,6 +164,7 @@ func extractField(value *reflect.Value, field *reflect.StructField, m *structCon
 	if m.ID == nil && field.Name == "ID" {
 		if f == nil {
 			f = &fieldConfig{
+				Index:          tagUniqueIdx,
 				Name:           field.Name,
 				IsZero:         isZero(value),
 				IsInteger:      isInteger(value),
diff --git a/extract_test.go b/extract_test.go
index ed8b119..1f6dcb0 100644
--- a/extract_test.go
+++ b/extract_test.go
@@ -45,7 +45,7 @@ func TestExtractUniqueTags(t *testing.T) {
 	require.False(t, infos.ID.IsZero)
 	require.Equal(t, "ClassicUnique", infos.Name)
 	require.Len(t, allByType(infos, "index"), 0)
-	require.Len(t, allByType(infos, "unique"), 4)
+	require.Len(t, allByType(infos, "unique"), 5)
 }
 
 func TestExtractIndexTags(t *testing.T) {
@@ -58,7 +58,7 @@ func TestExtractIndexTags(t *testing.T) {
 	require.False(t, infos.ID.IsZero)
 	require.Equal(t, "ClassicIndex", infos.Name)
 	require.Len(t, allByType(infos, "index"), 5)
-	require.Len(t, allByType(infos, "unique"), 0)
+	require.Len(t, allByType(infos, "unique"), 1)
 }
 
 func TestExtractInlineWithIndex(t *testing.T) {
@@ -70,7 +70,7 @@ func TestExtractInlineWithIndex(t *testing.T) {
 	require.NotNil(t, infos.ID)
 	require.Equal(t, "ClassicInline", infos.Name)
 	require.Len(t, allByType(infos, "index"), 3)
-	require.Len(t, allByType(infos, "unique"), 2)
+	require.Len(t, allByType(infos, "unique"), 3)
 }
 
 func TestExtractMultipleTags(t *testing.T) {
@@ -90,7 +90,7 @@ func TestExtractMultipleTags(t *testing.T) {
 	require.NotNil(t, infos.ID)
 	require.Equal(t, "User", infos.Name)
 	require.Len(t, allByType(infos, "index"), 2)
-	require.Len(t, allByType(infos, "unique"), 1)
+	require.Len(t, allByType(infos, "unique"), 2)
 
 	require.True(t, infos.Fields["Age"].Increment)
 	require.Equal(t, int64(1), infos.Fields["Age"].IncrementStart)
diff --git a/finder_test.go b/finder_test.go
index daec14a..c5a1c57 100644
--- a/finder_test.go
+++ b/finder_test.go
@@ -685,3 +685,20 @@ func TestPrefix(t *testing.T) {
 	err = db.Prefix("Group", "group3", &users)
 	require.Equal(t, ErrNotFound, err)
 }
+
+func TestPrefixWithID(t *testing.T) {
+	db, cleanup := createDB(t)
+	defer cleanup()
+
+	type User struct {
+		ID string
+	}
+
+	require.NoError(t, db.Save(&User{ID: "1"}))
+	require.NoError(t, db.Save(&User{ID: "10"}))
+
+	var users []User
+
+	require.NoError(t, db.Prefix("ID", "1", &users))
+	require.Len(t, users, 2)
+}