diff --git a/toolkit/xre/nsNativeAppSupportUnix.cpp b/toolkit/xre/nsNativeAppSupportUnix.cpp
index 380fbc4..6bbce50 100644
--- a/toolkit/xre/nsNativeAppSupportUnix.cpp
+++ b/toolkit/xre/nsNativeAppSupportUnix.cpp
@@ -205,7 +205,7 @@ static void ice_connection_watch(IceConn connection, IcePointer client_data,
 
     *watch_data = GUINT_TO_POINTER(watch_id);
   } else {
-    watch_id = GPOINTER_TO_UINT(*watch_data);
+    watch_id = (uint64_t)(*watch_data);
     g_source_remove(watch_id);
   }
 }