diff --git a/demos/full_waveform_inversion/full_waveform_inversion.py.rst b/demos/full_waveform_inversion/full_waveform_inversion.py.rst
index 45d200a05d..28794ee92d 100644
--- a/demos/full_waveform_inversion/full_waveform_inversion.py.rst
+++ b/demos/full_waveform_inversion/full_waveform_inversion.py.rst
@@ -261,6 +261,7 @@ To have the step 4, we need first to tape the forward problem. That is done by c
 
     from firedrake.adjoint import *
     continue_annotation()
+    get_working_tape().progress_bar = ProgressBar
 
 **Steps 2-3**: Solve the wave equation and compute the functional::
 
diff --git a/firedrake/progress_bar.py b/firedrake/progress_bar.py
index ce5d5f1cc1..bbfa9da5e5 100644
--- a/firedrake/progress_bar.py
+++ b/firedrake/progress_bar.py
@@ -11,7 +11,7 @@ def __init__(self, *args, **kwargs):
     def __enter__(self):
         pass
 
-    def __exit__(self):
+    def __exit__(self, *args, **kwargs):
         pass
 
     def iter(self, iterator):