diff --git a/extension.json b/extension.json
index db3cd50d4..b86a09631 100644
--- a/extension.json
+++ b/extension.json
@@ -215,7 +215,6 @@
 			"styles": "ext.math.css"
 		},
 		"ext.math.popup": {
-			"es6": true,
 			"packageFiles": "ext.math.popup.js",
 			"messages": [
 				"popups-settings-option-math",