diff --git a/git-svn.perl b/git-svn.perl
index 29f39c0831..38e1d5944d 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -519,7 +519,8 @@ sub cmd_dcommit {
 }
 
 sub cmd_find_rev {
-	my $revision_or_hash = shift;
+	my $revision_or_hash = shift or die "SVN or git revision required ",
+	                                    "as a command-line argument\n";
 	my $result;
 	if ($revision_or_hash =~ /^r\d+$/) {
 		my $head = shift;