diff --git a/tests/test_week_plan_frontend.py b/tests/test_week_plan_frontend.py
index e4d6a16..ba6adf1 100644
--- a/tests/test_week_plan_frontend.py
+++ b/tests/test_week_plan_frontend.py
@@ -2,6 +2,8 @@ import json
 import subprocess
 from pathlib import Path
 
+import pytest
+
 
 FRONTEND = Path(__file__).parents[1] / "frontend"
 CONTROLLER = FRONTEND / "week-plan.js"
@@ -400,16 +402,25 @@ console.log(JSON.stringify({queuedFirst,queuedSecond,resumed,confirmed,delivered
     assert result["state"]["revision"] == 9
 
 
-def test_week_controller_allows_only_one_tab_to_replay_the_shared_pull_queue():
-    result = run_controller("""
-const values=new Map(),held=new Set();
-const storage={getItem:key=>values.get(key)||null,setItem:(key,value)=>values.set(key,value),removeItem:key=>values.delete(key)};
-const locks={request:async(name,_options,work)=>{
+@pytest.mark.parametrize(
+    "coordinator_setup",
+    [
+        """const locks={request:async(name,_options,work)=>{
  if(held.has(name))return work(null);
  held.add(name);try{return await work({name});}finally{held.delete(name);}
 }};
 const coordinatorA=createOutboxCoordinator({storage,locks,channelFactory:null,tabId:'a'});
-const coordinatorB=createOutboxCoordinator({storage,locks,channelFactory:null,tabId:'b'});
+const coordinatorB=createOutboxCoordinator({storage,locks,channelFactory:null,tabId:'b'});""",
+        """const coordinatorA=createOutboxCoordinator({storage,locks:null,channelFactory:null,tabId:'a',now:()=>100});
+const coordinatorB=createOutboxCoordinator({storage,locks:null,channelFactory:null,tabId:'b',now:()=>100});""",
+    ],
+    ids=["navigator-lock", "storage-lease"],
+)
+def test_week_controller_allows_only_one_tab_to_replay_the_shared_pull_queue(coordinator_setup):
+    result = run_controller("""
+const values=new Map(),held=new Set();
+const storage={getItem:key=>values.get(key)||null,setItem:(key,value)=>values.set(key,value),removeItem:key=>values.delete(key)};
+COORDINATOR_SETUP
 let offline=true,posts=0,release;
 const gate=new Promise(resolve=>release=resolve);
 const fetchJson=async(_url,options={})=>{
@@ -431,7 +442,7 @@ const skipped=await second.flushPull();
 release();
 const confirmed=await firstFlush;
 console.log(JSON.stringify({posts,skipped,confirmed,pending:first.pendingPull()}));
-""")
+""".replace("COORDINATOR_SETUP", coordinator_setup))
 
     assert result["posts"] == 1
     assert result["skipped"]["lease_skipped"] is True