diff --git a/mozilla/editor/base/nsHTMLEditor.cpp b/mozilla/editor/base/nsHTMLEditor.cpp
index 2d01c47703c..5844c43c543 100644
--- a/mozilla/editor/base/nsHTMLEditor.cpp
+++ b/mozilla/editor/base/nsHTMLEditor.cpp
@@ -1511,6 +1511,7 @@ NS_IMETHODIMP nsHTMLEditor::InsertBreak()
   nsresult res;
   if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }
 
+  nsAutoRules beginRulesSniffing(this, kOpInsertBreak, nsIEditor::eNext);
   nsCOMPtr<nsIDOMSelection> selection;
   PRBool cancel, handled;
 
diff --git a/mozilla/editor/libeditor/html/nsHTMLEditor.cpp b/mozilla/editor/libeditor/html/nsHTMLEditor.cpp
index 2d01c47703c..5844c43c543 100644
--- a/mozilla/editor/libeditor/html/nsHTMLEditor.cpp
+++ b/mozilla/editor/libeditor/html/nsHTMLEditor.cpp
@@ -1511,6 +1511,7 @@ NS_IMETHODIMP nsHTMLEditor::InsertBreak()
   nsresult res;
   if (!mRules) { return NS_ERROR_NOT_INITIALIZED; }
 
+  nsAutoRules beginRulesSniffing(this, kOpInsertBreak, nsIEditor::eNext);
   nsCOMPtr<nsIDOMSelection> selection;
   PRBool cancel, handled;