diff --git a/mozilla/base/src/nsDeque.cpp b/mozilla/base/src/nsDeque.cpp
index aa7ca4e027c..ccff44af4b2 100644
--- a/mozilla/base/src/nsDeque.cpp
+++ b/mozilla/base/src/nsDeque.cpp
@@ -249,7 +249,7 @@ nsDequeIterator::nsDequeIterator(const nsDequeIterator& aCopy) :
  * @param   aCopy is an iterator to be copied from
  * @return  *this
  */
-nsDequeIterator& nsDequeIterator::operator=(nsDequeIterator& aCopy) {
+nsDequeIterator& nsDequeIterator::operator=(const nsDequeIterator& aCopy) {
   //queue's are already equal.
   mIndex=aCopy.mIndex;
   return *this;
diff --git a/mozilla/base/src/nsDeque.h b/mozilla/base/src/nsDeque.h
index b21382f42c1..df125683135 100644
--- a/mozilla/base/src/nsDeque.h
+++ b/mozilla/base/src/nsDeque.h
@@ -247,7 +247,7 @@ public:
    * @param 
    * @return
    */
-  nsDequeIterator& operator=(nsDequeIterator& aCopy);
+  nsDequeIterator& operator=(const nsDequeIterator& aCopy);
 
   /**
    * preform ! operation against to iterators to test for equivalence
diff --git a/mozilla/xpcom/ds/nsDeque.cpp b/mozilla/xpcom/ds/nsDeque.cpp
index aa7ca4e027c..ccff44af4b2 100644
--- a/mozilla/xpcom/ds/nsDeque.cpp
+++ b/mozilla/xpcom/ds/nsDeque.cpp
@@ -249,7 +249,7 @@ nsDequeIterator::nsDequeIterator(const nsDequeIterator& aCopy) :
  * @param   aCopy is an iterator to be copied from
  * @return  *this
  */
-nsDequeIterator& nsDequeIterator::operator=(nsDequeIterator& aCopy) {
+nsDequeIterator& nsDequeIterator::operator=(const nsDequeIterator& aCopy) {
   //queue's are already equal.
   mIndex=aCopy.mIndex;
   return *this;
diff --git a/mozilla/xpcom/ds/nsDeque.h b/mozilla/xpcom/ds/nsDeque.h
index b21382f42c1..df125683135 100644
--- a/mozilla/xpcom/ds/nsDeque.h
+++ b/mozilla/xpcom/ds/nsDeque.h
@@ -247,7 +247,7 @@ public:
    * @param 
    * @return
    */
-  nsDequeIterator& operator=(nsDequeIterator& aCopy);
+  nsDequeIterator& operator=(const nsDequeIterator& aCopy);
 
   /**
    * preform ! operation against to iterators to test for equivalence