diff --git a/git-difftool.perl b/git-difftool.perl
index 93e84e8d3..4555cd8b1 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -20,6 +20,7 @@
 
 sub usage
 {
+	my $exitcode = shift;
 	print << 'USAGE';
 usage: git difftool [-t|--tool=<tool>]
                     [-x|--extcmd=<cmd>]
@@ -27,7 +28,7 @@ sub usage
                     [--prompt] [-y|--no-prompt]
                     ['git diff' options]
 USAGE
-	exit 1;
+	exit($exitcode);
 }
 
 sub setup_environment
@@ -58,14 +59,14 @@ sub exe
 	'x|extcmd:s' => \$extcmd);
 
 if (defined($help)) {
-	usage();
+	usage(0);
 }
 if (defined($difftool_cmd)) {
 	if (length($difftool_cmd) > 0) {
 		$ENV{GIT_DIFF_TOOL} = $difftool_cmd;
 	} else {
 		print "No <tool> given for --tool=<tool>\n";
-		usage();
+		usage(1);
 	}
 }
 if (defined($extcmd)) {
@@ -73,7 +74,7 @@ sub exe
 		$ENV{GIT_DIFFTOOL_EXTCMD} = $extcmd;
 	} else {
 		print "No <cmd> given for --extcmd=<cmd>\n";
-		usage();
+		usage(1);
 	}
 }
 if ($gui) {