diff --git a/api/src/api/routes/invitation.py b/api/src/api/routes/invitation.py
index dc063a4..8138980 100644
--- a/api/src/api/routes/invitation.py
+++ b/api/src/api/routes/invitation.py
@@ -64,7 +64,7 @@ async def accept_user_space_invitation(request: Request):
         [{UserSpaceUser.invitation: invitation_id}, {UserSpaceUser.deleted: False}]
     )
     if user_space_user is None:
-        return JSONResponse({"error": "Invitation not found or already accepted."}, 404)
+        return _redirect_to_client()
 
     user_space_user.invitation = None
     await userSpaceUserDao.update(user_space_user)