diff --git a/git-difftool.perl b/git-difftool.perl
index a3ad38956..aba3d2f8c 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -29,12 +29,6 @@ sub usage
 	exit($exitcode);
 }
 
-sub setup_environment
-{
-	$ENV{GIT_PAGER} = '';
-	$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
-}
-
 # parse command-line options. all unrecognized options and arguments
 # are passed through to the 'git diff' command.
 my ($difftool_cmd, $extcmd, $gui, $help, $prompt);
@@ -79,7 +73,8 @@ sub setup_environment
 	}
 }
 
-setup_environment();
+$ENV{GIT_PAGER} = '';
+$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
 my @command = ('git', 'diff', @ARGV);
 
 # ActiveState Perl for Win32 does not implement POSIX semantics of