diff --git a/datasette/views/special.py b/datasette/views/special.py
index c80e816f..e997b788 100644
--- a/datasette/views/special.py
+++ b/datasette/views/special.py
@@ -75,6 +75,9 @@ class AuthTokenView(BaseView):
     has_json_alternate = False
 
     async def get(self, request):
+        # If already signed in as root, redirect
+        if request.actor and request.actor.get("id") == "root":
+            return Response.redirect(self.ds.urls.instance())
         token = request.args.get("token") or ""
         if not self.ds._root_token:
             raise Forbidden("Root token has already been used")
diff --git a/tests/test_auth.py b/tests/test_auth.py
index 74e8283a..fd7fcc65 100644
--- a/tests/test_auth.py
+++ b/tests/test_auth.py
@@ -26,6 +26,12 @@ async def test_auth_token(ds_client):
     # Check that a second with same token fails
     assert ds_client.ds._root_token is None
     assert (await ds_client.get(path)).status_code == 403
+    # But attempting with same token while logged in as root should redirect to /
+    response = await ds_client.get(
+        path, cookies={"ds_actor": ds_client.actor_cookie({"id": "root"})}
+    )
+    assert response.status_code == 302
+    assert response.headers["Location"] == "/"
 
 
 @pytest.mark.asyncio