diff --git a/packages/backend/src/server/api/endpoints/following/invalidate.ts b/packages/backend/src/server/api/endpoints/following/invalidate.ts
index 6287b2071..beeb1eb15 100644
--- a/packages/backend/src/server/api/endpoints/following/invalidate.ts
+++ b/packages/backend/src/server/api/endpoints/following/invalidate.ts
@@ -17,7 +17,7 @@ export const meta = {
 
 	kind: 'write:following',
 
-	errors: ['FOLLOWER_IS_YOURSELF', 'NO_SUCH_USER', 'NOT_FOLLOWING'],
+	errors: ['FOLLOWER_IS_YOURSELF', 'NO_SUCH_USER', 'NOT_FOLLOWED'],
 
 	res: {
 		type: 'object',
@@ -53,7 +53,7 @@ export default define(meta, paramDef, async (ps, user) => {
 		followeeId: followee.id,
 	});
 
-	if (!exist) throw new ApiError('NOT_FOLLOWING');
+	if (!exist) throw new ApiError('NOT_FOLLOWED');
 
 	await deleteFollowing(follower, followee);
 
diff --git a/packages/backend/src/server/api/error.ts b/packages/backend/src/server/api/error.ts
index 7636ab0ba..4af16383b 100644
--- a/packages/backend/src/server/api/error.ts
+++ b/packages/backend/src/server/api/error.ts
@@ -340,6 +340,10 @@ export const errors: Record<string, { message: string, httpStatusCode: number }>
 		message: 'You are not following that user.',
 		httpStatusCode: 409,
 	},
+	NOT_FOLLOWED: {
+		message: 'You are not followed by that user.',
+		httpStatusCode: 409,
+	},
 	NOT_LIKED: {
 		message: 'You have not liked that page.',
 		httpStatusCode: 409,