diff --git a/rhbz-966424.patch b/rhbz-966424.patch
new file mode 100644
index 0000000..37ddc6e
--- /dev/null
+++ b/rhbz-966424.patch
@@ -0,0 +1,24 @@
+diff --git a/toolkit/mozapps/shared/CertUtils.jsm b/toolkit/toolkit/mozapps/shared/CertUtils.jsm
+--- a/toolkit/mozapps/shared/CertUtils.jsm
++++ b/toolkit/mozapps/shared/CertUtils.jsm
+@@ -170,17 +170,19 @@ this.checkCert =
+   issuerCert = issuerCert.QueryInterface(Ci.nsIX509Cert3);
+   var tokenNames = issuerCert.getAllTokenNames({});
+ 
+   if (!tokenNames || !tokenNames.some(isBuiltinToken))
+     throw new Ce(certNotBuiltInErr, Cr.NS_ERROR_ABORT);
+ }
+ 
+ function isBuiltinToken(tokenName) {
+-  return tokenName == "Builtin Object Token";
++  return tokenName == "Builtin Object Token" ||
++         tokenName == "Default Trust" ||
++         tokenName == "System Trust";
+ }
+ 
+ /**
+  * This class implements nsIBadCertListener.  Its job is to prevent "bad cert"
+  * security dialogs from being shown to the user.  It is better to simply fail
+  * if the certificate is bad. See bug 304286.
+  *
+  * @param  aAllowNonBuiltInCerts (optional)
diff --git a/thunderbird.spec b/thunderbird.spec
index 32434e0..804f044 100644
--- a/thunderbird.spec
+++ b/thunderbird.spec
@@ -54,7 +54,7 @@
 Summary:        Mozilla Thunderbird mail/newsgroup client
 Name:           thunderbird
 Version:        17.0.6
-Release:        1%{?dist}
+Release:        2%{?dist}
 URL:            http://www.mozilla.org/projects/thunderbird/
 License:        MPLv1.1 or GPLv2+ or LGPLv2+
 Group:          Applications/Internet
@@ -86,6 +86,9 @@ Patch300:       xulrunner-16.0-jemalloc-ppc.patch
 Patch301:       rhbz-855923.patch
 Patch302:       mozilla-746112.patch
 
+# Fedora specific patches
+Patch400:       rhbz-966424.patch
+
 %if %{official_branding}
 # Required by Mozilla Corporation
 
@@ -172,6 +175,7 @@ cd mozilla
 %patch9 -p1 -b .791626
 %patch104 -p1 -b .gcc47
 %patch302 -p2 -b .746112
+%patch400 -p1 -b .966424
 cd ..
 
 %patch200 -p1 -b .addons
@@ -448,6 +452,9 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 #===============================================================================
 
 %changelog
+* Wed Jun 12 2013 Jan Horak <jhorak@redhat.com> - 17.0.6-2
+- Fixed rhbz#973371 - unable to install addons
+
 * Tue May 14 2013 Jan Horak <jhorak@redhat.com> - 17.0.6-1
 - Update to 17.0.6