diff --git a/graph_net/agent/parallel_extract.py b/graph_net/agent/parallel_extract.py
index ad1ab7384..0a6997814 100644
--- a/graph_net/agent/parallel_extract.py
+++ b/graph_net/agent/parallel_extract.py
@@ -226,9 +226,8 @@ def _orphan_watcher():
         return
 
     while True:
-        try:
-            model_id = task_queue.get_nowait()
-        except queue.Empty:
+        model_id = task_queue.get()
+        if model_id is None:
             break
 
         print(f"{prefix} Extracting: {model_id}", flush=True)
@@ -523,6 +522,9 @@ def main() -> int:
     task_queue: multiprocessing.Queue = multiprocessing.Queue()
     for mid in model_ids:
         task_queue.put(mid)
+    # Sentinel: each worker gets one None to signal shutdown
+    for _ in range(num_workers):
+        task_queue.put(None)
 
     # --- Launch workers ---
     result_queue: multiprocessing.Queue = multiprocessing.Queue()