--- polkit-0.112/src/programs/pkcheck.c.000	2017-02-01 13:52:45.000000000 +0100
+++ polkit-0.112/src/programs/pkcheck.c	2017-02-01 14:56:44.794337600 +0100
@@ -421,7 +421,11 @@ main (int argc, char *argv[])
 			  g_get_prgname (), "--system-bus-name");
               goto out;
             }
-
+          if (subject != NULL)
+            {
+              g_printerr ("--system-bus-name specified more than once\n");
+              goto out;
+            }
           subject = polkit_system_bus_name_new (argv[n]);
         }
       else if (g_strcmp0 (argv[n], "--action-id") == 0 || g_strcmp0 (argv[n], "-a") == 0)
@@ -433,7 +437,11 @@ main (int argc, char *argv[])
 			  g_get_prgname (), "--action-id");
               goto out;
             }
-
+          if (action_id != NULL)
+            {
+              g_printerr ("--action-id specified more than once\n");
+              goto out;
+            }
           action_id = g_strdup (argv[n]);
         }
       else if (g_strcmp0 (argv[n], "--detail") == 0 || g_strcmp0 (argv[n], "-d") == 0)