diff --git a/effect.h b/effect.h
index ee73f27d8..69a9eaf79 100644
--- a/effect.h
+++ b/effect.h
@@ -44,7 +44,7 @@ class effect {
 	int32 reset_count{ 0 };
 	uint32 reset_flag{ 0 };
 	uint32 count_code{ 0 };
-	uint32 category{ 0 };
+	uint64 category{ 0 };
 	uint32 hint_timing[2]{};
 	uint32 card_type{ 0 };
 	uint32 active_type{ 0 };