diff --git a/www/common/outer/testworker.js b/www/common/outer/testworker.js
index 849215da4..383aa0c62 100644
--- a/www/common/outer/testworker.js
+++ b/www/common/outer/testworker.js
@@ -1,4 +1,4 @@
 if (!self.crypto && !self.msCrypto) {
     throw new Error("E_NOCRYPTO");
 }
-postMessage("OK");
+self.postMessage("OK");