--- a/editor/libeditor/EditorBase.cpp
+++ b/editor/libeditor/EditorBase.cpp
@@ -4485,21 +4485,23 @@ EditorBase::DeleteSelectionAndCreateElem
 
   EditorRawDOMPoint pointToInsert(selection->AnchorRef());
   if (!pointToInsert.IsSet()) {
     return nullptr;
   }
   RefPtr<Element> newElement = CreateNode(&aTag, pointToInsert);
 
   // We want the selection to be just after the new node
-  DebugOnly<bool> advanced = pointToInsert.AdvanceOffset();
+  EditorRawDOMPoint afterNewElement(newElement);
+  MOZ_ASSERT(afterNewElement.IsSetAndValid());
+  DebugOnly<bool> advanced = afterNewElement.AdvanceOffset();
   NS_WARNING_ASSERTION(advanced,
                        "Failed to move offset next to the new element");
   ErrorResult error;
-  selection->Collapse(pointToInsert, error);
+  selection->Collapse(afterNewElement, error);
   if (NS_WARN_IF(error.Failed())) {
     // XXX Even if it succeeded to create new element, this returns error
     //     when Selection.Collapse() fails something.  This could occur with
     //     mutation observer or mutation event listener.
     error.SuppressException();
     return nullptr;
   }
   return newElement.forget();