diff --git a/intl/locale/src/os2/nsOS2Locale.cpp b/intl/locale/src/os2/nsOS2Locale.cpp
index 964ff8e58f43..87604b616db8 100644
--- a/intl/locale/src/os2/nsOS2Locale.cpp
+++ b/intl/locale/src/os2/nsOS2Locale.cpp
@@ -38,6 +38,7 @@
 #include "nsOS2Locale.h"
 #include "nsLocaleCID.h"
 #include "prprf.h"
+#include "nsReadableUtils.h"
 
 /* nsOS2Locale ISupports */
 NS_IMPL_ISUPPORTS1(nsOS2Locale,nsIOS2Locale)
diff --git a/intl/locale/src/os2/nsOS2Locale.h b/intl/locale/src/os2/nsOS2Locale.h
index 8a0d6777f59a..4665b6a2f87d 100644
--- a/intl/locale/src/os2/nsOS2Locale.h
+++ b/intl/locale/src/os2/nsOS2Locale.h
@@ -38,7 +38,7 @@ public:
    
   NS_IMETHOD GetPlatformLocale(PRUnichar* os2Locale,
                                 size_t length);
-  NS_IMETHOD GetXPLocale(const char* os2Locale, nsAutoString& locale);
+  NS_IMETHOD GetXPLocale(const char* os2Locale, nsAString& locale);
 
 protected:
   inline PRBool ParseLocaleString(const char* locale_string, char* language, char* country, char* extra, char separator);