--- cups-pk-helper-0.1.3/src/cups-pk-helper-mechanism.c	2011-09-02 11:30:26.000000000 +0200
+++ cups-pk-helper-0.1.3/src/cups-pk-helper-mechanism.c	2011-09-02 11:31:34.000000000 +0200
@@ -291,7 +291,7 @@ _check_polkit_for_action_internal (CphMe
                 return FALSE;
         }
 
-        if (!polkit_authorization_result_get_is_authorized (pk_result)) {
+        if (pk_result == NULL || !polkit_authorization_result_get_is_authorized (pk_result)) {
                 g_set_error (error,
                              CPH_MECHANISM_ERROR,
                              CPH_MECHANISM_ERROR_NOT_PRIVILEGED,