diff --git a/judge/judgedaemon.main.php b/judge/judgedaemon.main.php
index cb10a0db0f..b4385ac4c8 100644
--- a/judge/judgedaemon.main.php
+++ b/judge/judgedaemon.main.php
@@ -487,10 +487,14 @@ function fetch_executable_internal(
     return [$execrunpath, null, null];
 }
 
-$options = getopt("dv:n:hVe:j:t:", ["diskspace-error"]);
-// FIXME: getopt doesn't return FALSE on parse failure as documented!
-if ($options===false) {
-    echo "Error: parsing options failed.\n";
+$shortoptions = "dv:n:hVe:j:t:";
+$regex = "^([a-zA-Z0-9]:{0,2})*$"
+if (preg_match($regex, $shortoptions) !== 1) {
+    echo "Error: short options format specified is invalid.\n";
+}
+$options = getopt($shortoptions, ["diskspace-error"]);
+if ($options===false || !is_array($argv)) {
+    echo "Error: parsing options failed.\nPlease check: `register_argc_arg` in php.ini.\n";
     usage();
 }
 if (isset($options['v'])) {