lib/PublicInbox/Import.pm | 2 +-

diff --git a/lib/PublicInbox/Import.pm b/lib/PublicInbox/Import.pm
index 46f57e27c2b452d13f31cb3a08111620bb1308a8..3adf9dec21785ee9865a22bcdd8e7a338051dcac 100644
--- a/lib/PublicInbox/Import.pm
+++ b/lib/PublicInbox/Import.pm
@@ -25,7 +25,7 @@ 		my $r = popen_rd([qw(git config --global init.defaultBranch)],
 				 { GIT_CONFIG => undef });
 		chomp(my $h = <$r> // '');
 		close $r;
-		$h eq '' ? 'refs/heads/master' : $h;
+		$h eq '' ? 'refs/heads/master' : "refs/heads/$h";
 	}
 }