diff --git a/test/unit/strict-template-policy.html b/test/unit/strict-template-policy.html
index 982b3b97ff..4807c1762a 100644
--- a/test/unit/strict-template-policy.html
+++ b/test/unit/strict-template-policy.html
@@ -153,7 +153,7 @@
         window.onerror = window.top.onerror = window.uncaughtErrorFilter = 
           window.top.uncaughtErrorFilter = function(err) {
           if (!uncaughtError) {
-            uncaughtError = err instanceof Error ? err : new Error(err.message);
+            uncaughtError = err instanceof Error ? err : new Error(err.message || err);
           }
           return true;
         };