diff --git a/pyiron_base/jobs/master/serial.py b/pyiron_base/jobs/master/serial.py
index e16060bc3..3d72bdb59 100644
--- a/pyiron_base/jobs/master/serial.py
+++ b/pyiron_base/jobs/master/serial.py
@@ -381,6 +381,10 @@ def _init_child_job(self, parent):
         ):
             self.server.run_mode.interactive = True
 
+    def append(self, job):
+        with self.server.unlocked():
+            super().append(job)
+
 
 class GenericOutput(OrderedDict):
     """