diff --git a/thunderbird.desktop b/thunderbird.desktop
index 5aeb34c..1945d1e 100644
--- a/thunderbird.desktop
+++ b/thunderbird.desktop
@@ -8,7 +8,6 @@ TryExec=thunderbird
 Icon=thunderbird
 Terminal=false
 Type=Application
-StartupWMClass=Thunderbird-bin
 MimeType=message/rfc822;x-scheme-handler/mailto;
 StartupNotify=true
 Categories=Network;Email;
diff --git a/thunderbird.spec b/thunderbird.spec
index 0cb590f..cdc9209 100644
--- a/thunderbird.spec
+++ b/thunderbird.spec
@@ -40,7 +40,7 @@
 Summary:        Mozilla Thunderbird mail/newsgroup client
 Name:           thunderbird
 Version:        14.0
-Release:        2%{?dist}
+Release:        3%{?dist}
 URL:            http://www.mozilla.org/projects/thunderbird/
 License:        MPLv1.1 or GPLv2+ or LGPLv2+
 Group:          Applications/Internet
@@ -389,6 +389,9 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 #===============================================================================
 
 %changelog
+* Wed Aug 1 2012 Martin Stransky <stransky@redhat.com> - 14.0-3
+- removed StartupWMClass (rhbz#844863)
+
 * Sat Jul 21 2012 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 14.0-2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_18_Mass_Rebuild