diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 81b9b297724..8dbe0f169f6 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -2412,7 +2412,7 @@ FlushOneBuffer(Buffer buffer)
 
 	bufHdr = &BufferDescriptors[buffer - 1];
 
-	LWLockHeldByMe(bufHdr->content_lock);
+	Assert(LWLockHeldByMe(bufHdr->content_lock));
 
 	FlushBuffer(bufHdr, NULL);
 }