diff --git a/src/main/scala/xiangshan/backend/dispatch/DispatchQueue.scala b/src/main/scala/xiangshan/backend/dispatch/DispatchQueue.scala
index cff66810df69293c00213f84bcc2a141611e2af7..c5b1458e76808d31a1171c14af5bf263caded3e2 100644
--- a/src/main/scala/xiangshan/backend/dispatch/DispatchQueue.scala
+++ b/src/main/scala/xiangshan/backend/dispatch/DispatchQueue.scala
@@ -57,7 +57,7 @@ class DispatchQueue(size: Int, enqnum: Int, deqnum: Int, dpqType: Int) extends X
     Mux(
       left(indexWidth) === right(indexWidth),
       left(indexWidth - 1, 0) >= right(indexWidth - 1, 0),
-      left(indexWidth - 1, 0) < right(indexWidth - 1, 0)
+      left(indexWidth - 1, 0) <= right(indexWidth - 1, 0)
     )
   }
   XSError(!greaterOrEqualThan(tailPtr, headPtr), "assert greaterOrEqualThan(tailPtr, headPtr) failed\n")