diff --git a/CLI/cmux.swift b/CLI/cmux.swift
index a9ecd374f7ea..6a40e8123810 100644
--- a/CLI/cmux.swift
+++ b/CLI/cmux.swift
@@ -28512,8 +28512,11 @@ struct CMUXCLI {
                 // the ~60s-later idle_prompt Notification can consult it, and forwarded
                 // to the app so it can suppress the done-ping until work truly drains.
                 let hasPendingBackgroundWork = hasActiveClaudeBackgroundWork(parsedInput)
-                let hasUnsettledWork = stopFailure == nil && (hasPendingBackgroundWork
-                    || parsedInput.rawObject?["stop_hook_active"] as? Bool == true)
+                // Claude sets stop_hook_active on a re-entry after a Stop hook
+                // blocked once. That flag describes hook recursion, not work
+                // still running; only authoritative background-work signals
+                // should keep the sidebar in Running.
+                let hasUnsettledWork = stopFailure == nil && hasPendingBackgroundWork
 
                 // Update session with transcript summary and send completion notification.
                 let completion = stopFailure.map(claudeStopFailureSummary) ?? summarizeClaudeHookStop(
diff --git a/tests/test_claude_hook_stop_last_assistant.py b/tests/test_claude_hook_stop_last_assistant.py
index 2838273f5882..c1f6e2fbfb8e 100644
--- a/tests/test_claude_hook_stop_last_assistant.py
+++ b/tests/test_claude_hook_stop_last_assistant.py
@@ -155,12 +155,13 @@ def main() -> int:
     payload = {
         "session_id": f"sess-{uuid.uuid4().hex}",
         "hook_event_name": "Stop",
+        "stop_hook_active": True,
         "cwd": "/Users/lawrence/fun",
         "last_assistant_message": "2",
     }
 
     with CapturingSocketServer(workspace_id=workspace_id, surface_id=surface_id) as server:
-        env = os.environ.copy()
+        env = {key: value for key, value in os.environ.items() if not key.startswith("CMUX_")}
         env["CMUX_SOCKET_PATH"] = server.socket_path
         env["CMUX_WORKSPACE_ID"] = workspace_id
         env["CMUX_SURFACE_ID"] = surface_id
@@ -262,6 +263,14 @@ def main() -> int:
         if notifications[0] != expected:
             print(f"FAIL: incorrect semantic completion: {notifications[0]!r}")
             return 1
+        if not any(
+            command.startswith("set_status claude_code Idle ")
+            and f"--tab={workspace_id}" in command
+            and f"--panel={surface_id}" in command
+            for command in server.commands
+        ):
+            print(f"FAIL: final Stop with stop_hook_active=true did not settle Idle: {server.commands!r}")
+            return 1
 
     print("PASS: Claude cron guard denies durable jobs and Stop notification uses final assistant text")
     return 0