diff --git a/backend.go b/backend.go
index c10f1c8..eb6a77a 100644
--- a/backend.go
+++ b/backend.go
@@ -63,13 +63,6 @@ func (l lruBackend[K, V]) Purge() {
 	l.Cache.Flush()
 }
 
-type twoQueueBackend[K comparable, V any] struct {
-	*tq.Cache[K, V]
-	// As of Go 1.18, Go does not allow type alias of generic types, so we cannot write it like below and have to fall back
-	// to embedding in a struct.
-	// 	type twoQueueBackend[K comparable, V any] = *tq.Cache[K, V]
-}
-
 func new2QBackend[K comparable, V any](cap int) backend[K, V] {
-	return twoQueueBackend[K, V]{tq.New[K, V](cap)}
+	return tq.New[K, V](cap)
 }
diff --git a/cache_test.go b/cache_test.go
index 861afaa..7b91722 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -10,6 +10,8 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+
+	"github.com/motoki317/sc/tq"
 )
 
 func TestNewMust(t *testing.T) {
@@ -203,7 +205,7 @@ func TestNew(t *testing.T) {
 		c, err := New[string, string](fn, 0, 0, With2QBackend(10))
 		assert.NoError(t, err)
 		assert.IsType(t, &Cache[string, string]{}, c)
-		assert.IsType(t, twoQueueBackend[string, value[string]]{}, c.values)
+		assert.IsType(t, &tq.Cache[string, value[string]]{}, c.values)
 		assert.False(t, c.strictCoalescing)
 	})
 
@@ -213,7 +215,7 @@ func TestNew(t *testing.T) {
 		c, err := New[string, string](fn, 0, 0, With2QBackend(10), EnableStrictCoalescing())
 		assert.NoError(t, err)
 		assert.IsType(t, &Cache[string, string]{}, c)
-		assert.IsType(t, twoQueueBackend[string, value[string]]{}, c.values)
+		assert.IsType(t, &tq.Cache[string, value[string]]{}, c.values)
 		assert.True(t, c.strictCoalescing)
 	})
 }