diff --git a/superset/views/users/api.py b/superset/views/users/api.py
index 7f7202af41b5..79cc1ee1d109 100644
--- a/superset/views/users/api.py
+++ b/superset/views/users/api.py
@@ -116,6 +116,13 @@ def avatar(self, user_id: str) -> Response:
           description: >-
             Gets the avatar URL for the user with the given ID, or returns a 401 error
             if the user is unauthenticated.
+          parameters:
+            - in: path
+              name: user_id
+              required: true
+              description: The ID of the user
+              schema:
+                type: string
           responses:
             301:
               description: A redirect to the user's avatar URL