diff --git a/utils/scan-build b/utils/scan-build
index 5600b05..b3cb932 100755
--- a/utils/scan-build
+++ b/utils/scan-build
@@ -239,7 +239,7 @@
     shift @ARGV;
         
     if (!@ARGV) {
-      die "'-o' option requires a target directory name.";
+      die "$Prog: '-o' option requires a target directory name.\n";
     }
     
     $HtmlDir = shift @ARGV;
@@ -258,6 +258,8 @@
     next;
   }
   
+  die "$Prog: unrecognized option '$arg'\n" if ($arg =~ /^-/);
+  
   last;
 }