diff --git a/static/ui.js b/static/ui.js
index ccf0ca8b..fe308c82 100644
--- a/static/ui.js
+++ b/static/ui.js
@@ -18792,7 +18792,7 @@ function _workspaceSortComparator(key){
   const field=key==='created-desc'?'birthtime_ns':'mtime_ns';
   return (a,b)=>_compareWorkspaceTimestampDesc(a,b,field);
 }
-function _workspaceCreatedSortAvailable(){return !!S._workspaceBirthtimeSeen;}
+function _workspaceCreatedSortAvailable(){return !!(S.session&&S.session.workspace&&S._workspaceBirthtimeSeen);}
 function _effectiveWorkspaceSortKey(){
   const key=_normalizeWorkspaceSortKey(S.workspaceSortKey);
   return key==='created-desc'&&!_workspaceCreatedSortAvailable()?WORKSPACE_SORT_DEFAULT:key;
diff --git a/tests/test_issue6066_workspace_sort.py b/tests/test_issue6066_workspace_sort.py
index a2699f22..39e597e2 100644
--- a/tests/test_issue6066_workspace_sort.py
+++ b/tests/test_issue6066_workspace_sort.py
@@ -120,7 +120,7 @@ def _run_sort_harness(body):
     end = UI_JS.index("// ── Workspace preferences kebab menu", start)
     source = UI_JS[start:end]
     script = """
-global.S={showHiddenWorkspaceFiles:true,workspaceSortKey:'name-asc'};
+global.S={session:{workspace:'/test'},showHiddenWorkspaceFiles:true,workspaceSortKey:'name-asc'};
 global.localStorage={getItem(key){return key==='hermes-workspace-show-hidden-files'?'1':null},setItem(){}};
 global.$=()=>null;
 function _visibleWorkspaceEntries(entries){return S.showHiddenWorkspaceFiles?entries:entries.filter(()=>true)}
@@ -195,6 +195,16 @@ if(S._workspaceBirthtimeSeen!==false||S._workspaceBirthtimeWorkspace!=='')proces
     assert result.returncode == 0, result.stderr
 
 
+def test_session_teardown_disables_created_sort():
+    result = _run_sort_harness("""
+S._workspaceBirthtimeSeen=true;
+if(_workspaceCreatedSortAvailable()!==true)process.exit(1);
+S.session=null;
+if(_workspaceCreatedSortAvailable()!==false)process.exit(1);
+""")
+    assert result.returncode == 0, result.stderr
+
+
 def test_missing_timestamps_sort_last():
     result = _run_sort_harness("""
 S.workspaceSortKey='created-desc';S._workspaceBirthtimeSeen=true;