diff --git a/vacuum_gambit.p8 b/vacuum_gambit.p8
index 23c36b8..ac9a971 100644
--- a/vacuum_gambit.p8
+++ b/vacuum_gambit.p8
@@ -1201,7 +1201,7 @@ from further
    self.magnet += 2
   end,
  },
- self.main_gun.rate_upgrade_opt(),
+ self.main_gun:rate_upgrade_opt(),
 }
 
  if cdr > 0 then