diff --git a/Build.PL b/Build.PL
index 7fac4c2f..13cece25 100644
--- a/Build.PL
+++ b/Build.PL
@@ -130,7 +130,7 @@ if ($missing_prereqs) {
     if (eval "use App::Prove; 1") {
         App::Prove->new->run;
     }
-    if (!defined $ARGV[0] && $ARGV[0] ne '--gui') {
+    if (!defined $ARGV[0] || $ARGV[0] ne '--gui') {
         print "If you also want to use the GUI you can now run `perl Build.PL --gui` to install the required modules.\n";
     }
 }