diff --git a/src/main/scala/util/AsyncQueue.scala b/src/main/scala/util/AsyncQueue.scala
index 9c8732d7..af24597d 100644
--- a/src/main/scala/util/AsyncQueue.scala
+++ b/src/main/scala/util/AsyncQueue.scala
@@ -21,7 +21,7 @@ object AsyncGrayCounter {
         sink.io.d := source.io.q
         sink.io.en := Bool(true)
       }
-    syncv(0).io.d
+    syncv.head.io.q
   }
 }