diff --git a/tests/test_source_file/test_source_file.py b/tests/test_source_file/test_source_file.py
index a4b2a4e2d6..9752d89b49 100644
--- a/tests/test_source_file/test_source_file.py
+++ b/tests/test_source_file/test_source_file.py
@@ -51,8 +51,7 @@ def setup():
 
 def test_run1():
     openmc_path = pwd + '/../../src/openmc'
-#   if int(NoseMPI.mpi_np) > 0:
-    if False:
+    if int(NoseMPI.mpi_np) > 0:
         proc = Popen([NoseMPI.mpi_exec, '-np', NoseMPI.mpi_np, openmc_path],
                stderr=STDOUT, stdout=PIPE)
     else: