--- a/layout/forms/nsTextControlFrame.cpp
+++ b/layout/forms/nsTextControlFrame.cpp
@@ -1381,16 +1381,20 @@ nsTextControlFrame::CalcIntrinsicSize(ns
   }
 
   return NS_OK;
 }
 
 void
 nsTextControlFrame::DelayedEditorInit()
 {
+  // Make sure that editor init doesn't do things that would kill us off
+  // (especially off the script blockers it'll create for its DOM mutations).
+  nsAutoScriptBlocker scriptBlocker;
+
   // Time to mess with our security context... See comments in GetValue()
   // for why this is needed.
   nsCxPusher pusher;
   pusher.PushNull();
 
   InitEditor();
   // Notify the text listener we have focus and setup the caret etc (bug 446663).
   if (IsFocusedContent(PresContext(), GetContent())) {