diff --git a/doc/fixnavi.pl b/doc/fixnavi.pl
index 1d9d76d5a54d39c501ec6ca13bba48ce61ab8cb4..412ff6ca614d7548da0f49616115cafe21249419 100755
--- a/doc/fixnavi.pl
+++ b/doc/fixnavi.pl
@@ -1,5 +1,6 @@
-#! /usr/bin/perl -w
+#! /usr/bin/perl
 
+use warnings;
 use strict;
 
 my @files = ();