diff --git a/parser/html/nsHtml5TreeOpExecutor.cpp b/parser/html/nsHtml5TreeOpExecutor.cpp
index fe18bd35cdf9..44f74bf166a3 100644
--- a/parser/html/nsHtml5TreeOpExecutor.cpp
+++ b/parser/html/nsHtml5TreeOpExecutor.cpp
@@ -75,7 +75,7 @@ NS_IMPL_ADDREF_INHERITED(nsHtml5TreeOpExecutor, nsContentSink)
 NS_IMPL_RELEASE_INHERITED(nsHtml5TreeOpExecutor, nsContentSink)
 
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(nsHtml5TreeOpExecutor, nsContentSink)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMARRAY(mOwnedElements)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSTARRAY_OF_NSCOMPTR(mOwnedElements)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(nsHtml5TreeOpExecutor, nsContentSink)
diff --git a/parser/html/nsHtml5TreeOpExecutor.h b/parser/html/nsHtml5TreeOpExecutor.h
index 29ddcb362e9e..70f8a5ee51c3 100644
--- a/parser/html/nsHtml5TreeOpExecutor.h
+++ b/parser/html/nsHtml5TreeOpExecutor.h
@@ -53,7 +53,6 @@
 #include "nsHtml5DocumentMode.h"
 #include "nsIScriptElement.h"
 #include "nsIParser.h"
-#include "nsCOMArray.h"
 #include "nsAHtml5TreeOpSink.h"
 #include "nsHtml5TreeOpStage.h"
 #include "nsIURI.h"
@@ -104,7 +103,7 @@ class nsHtml5TreeOpExecutor : public nsContentSink,
     nsTArray<nsIContentPtr>              mElementsSeenInThisAppendBatch;
     nsTArray<nsHtml5PendingNotification> mPendingNotifications;
     nsHtml5StreamParser*                 mStreamParser;
-    nsCOMArray<nsIContent>               mOwnedElements;
+    nsTArray<nsCOMPtr<nsIContent> >      mOwnedElements;
     
     /**
      * URLs already preloaded/preloading.
@@ -393,7 +392,7 @@ class nsHtml5TreeOpExecutor : public nsContentSink,
     void Reset();
     
     inline void HoldElement(nsIContent* aContent) {
-      mOwnedElements.AppendObject(aContent);
+      mOwnedElements.AppendElement(aContent);
     }
 
     void DropHeldElements();