diff --git a/editor/libeditor/nsEditorUtils.cpp b/editor/libeditor/nsEditorUtils.cpp
index 3e7433dd2856..b0047a518e46 100644
--- a/editor/libeditor/nsEditorUtils.cpp
+++ b/editor/libeditor/nsEditorUtils.cpp
@@ -92,7 +92,7 @@ nsDOMIterator::~nsDOMIterator()
 }
 
 void
-nsDOMIterator::AppendList(nsBoolDomIterFunctor& functor,
+nsDOMIterator::AppendList(const nsBoolDomIterFunctor& functor,
                           nsTArray<nsCOMPtr<nsINode>>& arrayOfNodes) const
 {
   // Iterate through dom and build list
@@ -106,7 +106,7 @@ nsDOMIterator::AppendList(nsBoolDomIterFunctor& functor,
 }
 
 void
-nsDOMIterator::AppendList(nsBoolDomIterFunctor& functor,
+nsDOMIterator::AppendList(const nsBoolDomIterFunctor& functor,
                           nsCOMArray<nsIDOMNode>& arrayOfNodes) const
 {
   // iterate through dom and build list
diff --git a/editor/libeditor/nsEditorUtils.h b/editor/libeditor/nsEditorUtils.h
index e76c3f064251..c35287c0a1df 100644
--- a/editor/libeditor/nsEditorUtils.h
+++ b/editor/libeditor/nsEditorUtils.h
@@ -167,8 +167,8 @@ class MOZ_STACK_CLASS nsAutoUpdateViewBatch
 class nsBoolDomIterFunctor 
 {
   public:
-    virtual bool operator()(nsIDOMNode* aNode)=0;
-    bool operator()(nsINode* aNode)
+    virtual bool operator()(nsIDOMNode* aNode) const = 0;
+    bool operator()(nsINode* aNode) const
     {
       return operator()(GetAsDOMNode(aNode));
     }
@@ -181,9 +181,9 @@ class MOZ_STACK_CLASS nsDOMIterator
     explicit nsDOMIterator(nsIDOMNode& aNode);
     virtual ~nsDOMIterator();
 
-    void AppendList(nsBoolDomIterFunctor& functor,
+    void AppendList(const nsBoolDomIterFunctor& functor,
                     nsTArray<nsCOMPtr<nsINode>>& arrayOfNodes) const;
-    void AppendList(nsBoolDomIterFunctor& functor,
+    void AppendList(const nsBoolDomIterFunctor& functor,
                     nsCOMArray<nsIDOMNode>& arrayOfNodes) const;
   protected:
     nsCOMPtr<nsIContentIterator> mIter;
@@ -202,7 +202,8 @@ class MOZ_STACK_CLASS nsDOMSubtreeIterator : public nsDOMIterator
 class nsTrivialFunctor : public nsBoolDomIterFunctor
 {
   public:
-    virtual bool operator()(nsIDOMNode* aNode)  // used to build list of all nodes iterator covers
+    // Used to build list of all nodes iterator covers
+    virtual bool operator()(nsIDOMNode* aNode) const
     {
       return true;
     }
diff --git a/editor/libeditor/nsHTMLEditRules.cpp b/editor/libeditor/nsHTMLEditRules.cpp
index 525167462b7b..9fd0e90743b3 100644
--- a/editor/libeditor/nsHTMLEditRules.cpp
+++ b/editor/libeditor/nsHTMLEditRules.cpp
@@ -107,7 +107,8 @@ IsStyleCachePreservingAction(EditAction action)
 class nsTableCellAndListItemFunctor : public nsBoolDomIterFunctor
 {
   public:
-    virtual bool operator()(nsIDOMNode* aNode)  // used to build list of all li's, td's & th's iterator covers
+    // Used to build list of all li's, td's & th's iterator covers
+    virtual bool operator()(nsIDOMNode* aNode) const
     {
       if (nsHTMLEditUtils::IsTableCell(aNode)) return true;
       if (nsHTMLEditUtils::IsListItem(aNode)) return true;
@@ -118,7 +119,7 @@ class nsTableCellAndListItemFunctor : public nsBoolDomIterFunctor
 class nsBRNodeFunctor : public nsBoolDomIterFunctor
 {
   public:
-    virtual bool operator()(nsIDOMNode* aNode)  
+    virtual bool operator()(nsIDOMNode* aNode) const
     {
       if (nsTextEditUtils::IsBreak(aNode)) return true;
       return false;
@@ -129,7 +130,7 @@ class nsEmptyEditableFunctor : public nsBoolDomIterFunctor
 {
   public:
     explicit nsEmptyEditableFunctor(nsHTMLEditor* editor) : mHTMLEditor(editor) {}
-    virtual bool operator()(nsIDOMNode* aNode)  
+    virtual bool operator()(nsIDOMNode* aNode) const
     {
       if (mHTMLEditor->IsEditable(aNode) &&
         (nsHTMLEditUtils::IsListItem(aNode) ||
@@ -151,7 +152,7 @@ class nsEditableTextFunctor : public nsBoolDomIterFunctor
 {
   public:
     explicit nsEditableTextFunctor(nsHTMLEditor* editor) : mHTMLEditor(editor) {}
-    virtual bool operator()(nsIDOMNode* aNode)  
+    virtual bool operator()(nsIDOMNode* aNode) const
     {
       if (nsEditor::IsTextNode(aNode) && mHTMLEditor->IsEditable(aNode)) 
       {
@@ -5864,7 +5865,8 @@ public:
   explicit nsUniqueFunctor(nsCOMArray<nsIDOMNode> &aArray) : mArray(aArray)
   {
   }
-  virtual bool operator()(nsIDOMNode* aNode)  // used to build list of all nodes iterator covers
+  // used to build list of all nodes iterator covers
+  virtual bool operator()(nsIDOMNode* aNode) const
   {
     return mArray.IndexOf(aNode) < 0;
   }