diff --git a/packages/frontend/src/custom-emojis.ts b/packages/frontend/src/custom-emojis.ts
index b4b6dff570..91784bb2cd 100644
--- a/packages/frontend/src/custom-emojis.ts
+++ b/packages/frontend/src/custom-emojis.ts
@@ -17,7 +17,7 @@ export const customEmojiCategories = computed<[ ...string[], null ]>(() => {
 			categories.add(emoji.category);
 		}
 	}
-	return markRaw([...Array.from(categories), null]);
+	return markRaw([...Array.from(categories).sort(), null]);
 });
 
 export function compareBySortKey(a: Misskey.entities.EmojiSimple, b: Misskey.entities.EmojiSimple): number {