diff --git a/src/server/api/endpoints/blocking/create.ts b/src/server/api/endpoints/blocking/create.ts
index 850406908..4deaa3997 100644
--- a/src/server/api/endpoints/blocking/create.ts
+++ b/src/server/api/endpoints/blocking/create.ts
@@ -66,10 +66,6 @@ export default define(meta, async (ps, user) => {
 		throw new ApiError(meta.errors.blockeeIsYourself);
 	}
 
-	if (user.isAdmin || user.isModerator) {
-		throw new ApiError(meta.errors.cannotBlockModerator);
-	}
-
 	// Get blockee
 	const blockee = await getUser(ps.userId).catch(e => {
 		if (e.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
@@ -86,8 +82,12 @@ export default define(meta, async (ps, user) => {
 		throw new ApiError(meta.errors.alreadyBlocking);
 	}
 
-	// Create blocking
-	await create(blocker, blockee);
+	try {
+		await create(blocker, blockee);
+	} catch (e) {
+		if (e.id === 'e42b7890-5e4d-9d9c-d54b-cf4dd30adfb5') throw new ApiError(meta.errors.cannotBlockModerator);
+		throw e;
+	}
 
 	NoteWatchings.delete({
 		userId: blocker.id,
diff --git a/src/services/blocking/create.ts b/src/services/blocking/create.ts
index 76c4bda9d..defe37751 100644
--- a/src/services/blocking/create.ts
+++ b/src/services/blocking/create.ts
@@ -9,8 +9,13 @@ import { User } from '@/models/entities/user';
 import { Blockings, Users, FollowRequests, Followings, UserListJoinings, UserLists } from '@/models/index';
 import { perUserFollowingChart } from '@/services/chart/index';
 import { genId } from '@/misc/gen-id';
+import { IdentifiableError } from '@/misc/identifiable-error';
 
 export default async function(blocker: User, blockee: User) {
+	if (blockee.isAdmin || blockee.isModerator) {
+		throw new IdentifiableError('e42b7890-5e4d-9d9c-d54b-cf4dd30adfb5');
+	}
+
 	await Promise.all([
 		cancelRequest(blocker, blockee),
 		cancelRequest(blockee, blocker),