diff --git a/osu.Game/Beatmaps/Legacy/LegacyMods.cs b/osu.Game/Beatmaps/Legacy/LegacyMods.cs
index 583e950e49..0e517ea3df 100644
--- a/osu.Game/Beatmaps/Legacy/LegacyMods.cs
+++ b/osu.Game/Beatmaps/Legacy/LegacyMods.cs
@@ -38,5 +38,6 @@ namespace osu.Game.Beatmaps.Legacy
         Key1 = 1 << 26,
         Key3 = 1 << 27,
         Key2 = 1 << 28,
+        Mirror = 1 << 30,
     }
 }