diff --git a/lib/Lacuna/DB/Result/Mission.pm b/lib/Lacuna/DB/Result/Mission.pm
index 4347adb0..15b0f70d 100644
--- a/lib/Lacuna/DB/Result/Mission.pm
+++ b/lib/Lacuna/DB/Result/Mission.pm
@@ -86,7 +86,7 @@ sub add_next_part {
     else {
         $ext =~ m/^part(\d+)$/;
         my $part = $1 + 1;
-        $name .= '.part'.$1;
+        $name .= '.part'.$part;
     }
     return Lacuna::DB::Result::Mission->initialize($self->zone, $name);
 }