diff --git a/labscript_devices/FunctionRunner/labscript_devices.py b/labscript_devices/FunctionRunner/labscript_devices.py
index 5f5b04a7..804fd937 100644
--- a/labscript_devices/FunctionRunner/labscript_devices.py
+++ b/labscript_devices/FunctionRunner/labscript_devices.py
@@ -90,7 +90,7 @@ def func(shot_context, t, ...):
     def generate_code(self, hdf5_file):
         # Python's sorting is stable, so items with equal times will remain in the order
         # they were added
-        self.functions.sort()
+        self.functions.sort(key=lambda item: item[0])
         vlenstr = h5py.special_dtype(vlen=str)
         table_dtypes = [
             ('t', float),