--- a/accessible/src/html/nsHyperTextAccessible.cpp
+++ b/accessible/src/html/nsHyperTextAccessible.cpp
@@ -1648,17 +1648,17 @@ PRInt32 nsHyperTextAccessible::GetCaretL
   domSel->GetFocusOffset(&caretOffset);
   nsFrameSelection::HINT hint = frameSelection->GetHint();
   nsIFrame *caretFrame = frameSelection->GetFrameForNodeOffset(caretContent, caretOffset,
                                                                hint, &returnOffsetUnused);
   NS_ENSURE_TRUE(caretFrame, -1);
 
   PRInt32 lineNumber = 1;
   nsAutoLineIterator lineIterForCaret;
-  nsIContent *hyperTextContent = IsContent() ? mContent : nsnull;
+  nsIContent *hyperTextContent = IsContent() ? mContent.get() : nsnull;
   while (caretFrame) {
     if (hyperTextContent == caretFrame->GetContent()) {
       return lineNumber; // Must be in a single line hyper text, there is no line iterator
     }
     nsIFrame *parentFrame = caretFrame->GetParent();
     if (!parentFrame)
       break;