diff --git a/src/net.h b/src/net.h
index 39b76d38f..8a39577b1 100644
--- a/src/net.h
+++ b/src/net.h
@@ -480,6 +480,7 @@ public:
     void Release()
     {
         nRefCount--;
+        assert(nRefCount >= 0);
     }