diff --git a/src/dawn/wire/client/RequestTracker.h b/src/dawn/wire/client/RequestTracker.h
index d1d6cc0..13b7294 100644
--- a/src/dawn/wire/client/RequestTracker.h
+++ b/src/dawn/wire/client/RequestTracker.h
@@ -72,7 +72,7 @@
     }
 
   private:
-    uint64_t mSerial;
+    uint64_t mSerial = 0;
     std::map<uint64_t, Request> mRequests;
 };