diff --git a/artiq/master/worker_impl.py b/artiq/master/worker_impl.py
index 8da3a3fd3..c4fc6ccf8 100644
--- a/artiq/master/worker_impl.py
+++ b/artiq/master/worker_impl.py
@@ -5,6 +5,7 @@ from artiq.protocols import pyon
 from artiq.tools import file_import
 from artiq.master.worker_db import DBHub, ResultDB
 from artiq.master.results import get_hdf5_output
+from artiq.language.experiment import is_experiment
 
 
 def get_object():