diff --git a/kdelibs-4.8.4-kjs-locale.patch b/kdelibs-4.8.4-kjs-locale.patch
new file mode 100644
index 0000000..74ba0f9
--- /dev/null
+++ b/kdelibs-4.8.4-kjs-locale.patch
@@ -0,0 +1,18 @@
+diff -up kdelibs-4.8.4/khtml/ecma/kjs_navigator.cpp.me kdelibs-4.8.4/khtml/ecma/kjs_navigator.cpp
+--- kdelibs-4.8.4/khtml/ecma/kjs_navigator.cpp.me	2012-06-06 22:49:52.542044112 +0200
++++ kdelibs-4.8.4/khtml/ecma/kjs_navigator.cpp	2012-07-12 11:52:50.973049316 +0200
+@@ -261,7 +261,13 @@ JSValue *Navigator::getValueProperty(Exe
+   case BrowserLanguage:
+   case Language:
+   case UserLanguage:
+-    return jsString(KGlobal::locale()->language());
++  {
++    QString l =  KGlobal::locale()->language();
++    if ( l.contains(QLatin1Char('_')) )
++      return jsString(l.replace(QLatin1Char('_'), QLatin1Char('-')));
++    else
++      return jsString(l + QLatin1Char('-') + KGlobal::locale()->country().toUpper());
++  }
+   case UserAgent:
+     return jsString(userAgent);
+   case Platform:
diff --git a/kdelibs.spec b/kdelibs.spec
index 633fec0..81f42c0 100644
--- a/kdelibs.spec
+++ b/kdelibs.spec
@@ -25,7 +25,7 @@
 
 Summary: KDE Libraries
 Version: 4.8.4
-Release: 6%{?dist}
+Release: 7%{?dist}
 
 Name: kdelibs
 Epoch: 6
@@ -142,6 +142,9 @@ Patch52: kdelibs-4.7.4-SOLID_UPNP.patch
 # add s390/s390x support in kjs
 Patch53: kdelibs-4.7.2-kjs-s390.patch
 
+# return valid locale (RFC 1766)
+Patch54: kdelibs-4.8.4-kjs-locale.patch
+
 ## upstream
 # fix kdeclarative install location (by wstephenson as found in kde-packager list)
 Patch100: kdelibs-4.8.3-kdeclarative-install-location.patch
@@ -356,6 +359,7 @@ popd
 %patch51 -p1 -b .uri_mimetypes
 %patch52 -p1 -b .SOLID_UPNP
 %patch53 -p1 -b .kjs-s390
+%patch54 -p1 -b .kjs-locale
 
 # upstream patches
 %patch100 -p1 -b .kdeclarative-install-location
@@ -615,6 +619,9 @@ rm -rf %{buildroot}
 
 
 %changelog
+* Thu Jul 12 2012 Than Ngo <than@redhat.com> - 6:4.8.4-7
+- fix kjs to return valid lang (RFC 1766)
+
 * Fri Jun 29 2012 Lukáš Tinkl <ltinkl@redhat.com> - 6:4.8.4-6
 - sync the udisks2 backend patch