diff --git a/mozilla/extensions/xmlterm/base/mozXMLTermSession.cpp b/mozilla/extensions/xmlterm/base/mozXMLTermSession.cpp
index 4edd180b578..1fb52f51ab0 100644
--- a/mozilla/extensions/xmlterm/base/mozXMLTermSession.cpp
+++ b/mozilla/extensions/xmlterm/base/mozXMLTermSession.cpp
@@ -56,6 +56,7 @@
 #include "mozXMLTermUtils.h"
 #include "mozXMLTermSession.h"
 #include "nsISelectionController.h"
+#include "nsReadableUtils.h"
 
 /////////////////////////////////////////////////////////////////////////
 // mozXMLTermSession definition