diff --git a/include/metatile_behavior.h b/include/metatile_behavior.h
index d49dc2459a..5bb95bc18e 100644
--- a/include/metatile_behavior.h
+++ b/include/metatile_behavior.h
@@ -148,8 +148,8 @@ bool8 MetatileBehavior_IsQuestionnaire(u8);
 bool8 MetatileBehavior_IsLongGrass_Duplicate(u8);
 bool8 MetatileBehavior_IsLongGrassSouthEdge(u8);
 bool8 MetatileBehavior_IsTrainerHillTimer(u8);
-bool32 MetatileBehavior_IsSignpost(u32 mb);
-bool32 MetatileBehavior_IsPokemonCenterSign(u32 mb);
-bool32 MetatileBehavior_IsPokeMartSign(u32 mb);
+bool32 MetatileBehavior_IsSignpost(u32);
+bool32 MetatileBehavior_IsPokemonCenterSign(u32);
+bool32 MetatileBehavior_IsPokeMartSign(u32);
 
 #endif // GUARD_METATILE_BEHAVIOR_H