diff --git a/src/field/arena.ts b/src/field/arena.ts
index 10e6b5f1d7d..bdd35394417 100644
--- a/src/field/arena.ts
+++ b/src/field/arena.ts
@@ -836,7 +836,7 @@ export class Arena {
    * @todo Review the other tag manipulation functions to see if they can be migrated towards using this (more efficient)
    */
   public removeTagsOnSide(
-    tagTypes: ArenaTagType[] | ReadonlyArray<ArenaTagType>,
+    tagTypes: ArenaTagType[] | readonly ArenaTagType[],
     side: ArenaTagSide,
     quiet = false,
   ): void {