1 files changed, 4 insertions, 4 deletions
diff --git a/dom/base/ChildIterator.cpp b/dom/base/ChildIterator.cpp
index ae5f4665d7..7a0a705da9 100644
--- a/dom/base/ChildIterator.cpp
+++ b/dom/base/ChildIterator.cpp
@@ -192,17 +192,17 @@ FlattenedChildIterator::Init(bool aIgnoreXBL)
 }
 
 bool
-ExplicitChildIterator::Seek(nsIContent* aChildToFind)
+ExplicitChildIterator::Seek(const nsIContent* aChildToFind)
 {
   if (aChildToFind->GetParent() == mParent &&
       !aChildToFind->IsRootOfAnonymousSubtree()) {
     // Fast path: just point ourselves to aChildToFind, which is a
     // normal DOM child of ours.
-    MOZ_ASSERT(!nsContentUtils::IsContentInsertionPoint(aChildToFind));
-    mChild = aChildToFind;
+    mChild = const_cast<nsIContent*>(aChildToFind);
     mIndexInInserted = 0;
     mDefaultChild = nullptr;
     mIsFirst = false;
+    MOZ_ASSERT(!nsContentUtils::IsContentInsertionPoint(mChild));
     return true;
   }
 
@@ -348,7 +348,7 @@ AllChildrenIterator::Get() const
 
 
 bool
-AllChildrenIterator::Seek(nsIContent* aChildToFind)
+AllChildrenIterator::Seek(const nsIContent* aChildToFind)
 {
   if (mPhase == eAtBegin || mPhase == eAtBeforeKid) {
     mPhase = eAtExplicitKids;