diff --git a/backends/yum/helpers/yumBackend.py b/backends/yum/helpers/yumBackend.py
index f2c3f82..d434006 100644
--- a/backends/yum/helpers/yumBackend.py
+++ b/backends/yum/helpers/yumBackend.py
@@ -1376,15 +1376,16 @@ class PackageKitYumBackend(PackageKitBaseBackend):
             desc = notice['description']
             # Update References (Bugzilla,CVE ...)
             refs = notice['references']
-            for ref in refs:
-                typ = ref['type']
-                href = ref['href']
-                title = ref['title'] or ""
-                if href:
-                    if typ in ('bugzilla','cve'):
-                        urls[typ].append("%s;%s" % (href,title))
-                    else:
-                        urls['vendor'].append("%s;%s" % (href,title))
+            if refs:
+                for ref in refs:
+                    typ = ref['type']
+                    href = ref['href']
+                    title = ref['title'] or ""
+                    if href:
+                        if typ in ('bugzilla','cve'):
+                            urls[typ].append("%s;%s" % (href,title))
+                        else:
+                            urls['vendor'].append("%s;%s" % (href,title))
 
             # Reboot flag
             if notice.get_metadata().has_key('reboot_suggested') and notice['reboot_suggested']: