diff --git a/chrome/content/zotero/tools/testTranslators/translatorTester.js b/chrome/content/zotero/tools/testTranslators/translatorTester.js
index 51b1912b55..a56244b919 100644
--- a/chrome/content/zotero/tools/testTranslators/translatorTester.js
+++ b/chrome/content/zotero/tools/testTranslators/translatorTester.js
@@ -30,7 +30,12 @@ var EXPORTED_SYMBOLS = ["Zotero_TranslatorTesters"];
 // For debugging specific translators by label
 var includeTranslators = [];
 
-this.Zotero = typeof Zotero != 'undefined' ? Zotero : null;
+try {
+	Zotero;
+}
+catch (e) {
+	var Zotero;
+}
 
 var Zotero_TranslatorTesters = new function() {
 	const TEST_TYPES = ["web", "import", "export", "search"];