diff --git a/extensions/inspector/base/src/inLayoutUtils.cpp b/extensions/inspector/base/src/inLayoutUtils.cpp
index fa31eb6338c..7d231f22c35 100644
--- a/extensions/inspector/base/src/inLayoutUtils.cpp
+++ b/extensions/inspector/base/src/inLayoutUtils.cpp
@@ -62,7 +62,7 @@ inLayoutUtils::GetWindowFor(nsIDOMNode* aNode)
 {
   nsCOMPtr<nsIDOMDocument> doc1;
   aNode->GetOwnerDocument(getter_AddRefs(doc1));
-  return GetWindowFor(doc1);
+  return GetWindowFor(doc1.get());
 }
 
 nsIDOMWindowInternal*