diff --git a/pympipool/shared/executorbase.py b/pympipool/shared/executorbase.py
index 9e75f31a..8e64096a 100644
--- a/pympipool/shared/executorbase.py
+++ b/pympipool/shared/executorbase.py
@@ -55,10 +55,17 @@ def shutdown(self, wait=True, *, cancel_futures=False):
         self._future_queue.put({"shutdown": True, "wait": wait})
         self._process.join()
         self._future_queue.join()
+        self._process = None
 
     def __len__(self):
         return self._future_queue.qsize()
 
+    def __del__(self):
+        try:
+            self.shutdown(wait=True)
+        except (AttributeError, RuntimeError):
+            pass
+
     def _set_init_function(self, init_function):
         if init_function is not None:
             self._future_queue.put(