diff --git a/unittest/python/python-open.py b/unittest/python/python-open.py
index 6153e032e3..67500ea6fa 100644
--- a/unittest/python/python-open.py
+++ b/unittest/python/python-open.py
@@ -4,6 +4,7 @@ from lammps import lammps
 
 has_mpi=False
 has_mpi4py=False
+has_exceptions=False
 try:
     from mpi4py import __version__ as mpi4py_version
     # tested to work with mpi4py versions 2 and 3