diff --git a/app/assets/javascripts/discourse/lib/Markdown.Editor.js b/app/assets/javascripts/discourse/lib/Markdown.Editor.js
index ac8e2ad929d..148ae87c91b 100644
--- a/app/assets/javascripts/discourse/lib/Markdown.Editor.js
+++ b/app/assets/javascripts/discourse/lib/Markdown.Editor.js
@@ -1420,7 +1420,7 @@
 
             inputBox.focus();
 
-            if (button.textOp) {
+            if (button && button.textOp) {
 
                 if (undoManager) {
                     undoManager.setCommandMode();