diff --git a/content/base/src/nsGenericElement.cpp b/content/base/src/nsGenericElement.cpp
index bd343023eb66..f903e4658420 100644
--- a/content/base/src/nsGenericElement.cpp
+++ b/content/base/src/nsGenericElement.cpp
@@ -2445,7 +2445,7 @@ nsGenericElement::doInsertBefore(nsIDOMNode* aNewChild,
       return res;
     }
 
-    if (!do_notify && mDocument) {
+    if (count && !do_notify && mDocument) {
       mDocument->ContentAppended(this, old_count);
     }