diff --git a/backend/app/routers/websites.py b/backend/app/routers/websites.py
index 241ec94..a2bd3fb 100644
--- a/backend/app/routers/websites.py
+++ b/backend/app/routers/websites.py
@@ -314,7 +314,7 @@ def create_website_group(
         raise HTTPException(502, str(exc))
 
 
-@router.put("/api/websites/{wid}/groups/{group_id}", response_model=dict)
+@router.put("/api/websites/{wid}/groups/{group_id:path}", response_model=dict)
 def update_website_group(
     wid: int,
     group_id: str,
diff --git a/backend/test_website_group_mgmt.py b/backend/test_website_group_mgmt.py
index 7a8c489..5ec1fa0 100644
--- a/backend/test_website_group_mgmt.py
+++ b/backend/test_website_group_mgmt.py
@@ -42,7 +42,7 @@ def test_create_and_update_website_group(db_session, monkeypatch):
 
     b = WebsiteGroupBinding(
         website_id=w.id,
-        target_group_id="g123",
+        target_group_id="g/123",
         target_group_name="OldName",
         source_groups_json="[]",
         enabled=True
@@ -81,12 +81,12 @@ def test_create_and_update_website_group(db_session, monkeypatch):
 
     # 2. Test update_website_group
     body_update = WebsiteGroupUpdate(name="UpdatedGroup", description="UpdatedDesc")
-    res_update = update_website_group(wid=w.id, group_id="g123", body=body_update, db=db_session)
-    assert res_update["id"] == "g123"
+    res_update = update_website_group(wid=w.id, group_id="g/123", body=body_update, db=db_session)
+    assert res_update["id"] == "g/123"
     assert res_update["name"] == "UpdatedGroup"
     assert res_update["description"] == "UpdatedDesc"
     assert len(called_update) == 1
-    assert called_update[0][1] == "g123"
+    assert called_update[0][1] == "g/123"
     assert called_update[0][2] == {"name": "UpdatedGroup", "description": "UpdatedDesc"}
 
     # Verify that local binding was updated