diff --git a/workflow/tests/test_pool_and_psuedoreplicate.py b/workflow/tests/test_pool_and_psuedoreplicate.py
index 38b100479cceb4b55a742cf3ba01a6aa772dfe5c..cd6b137d591e73020a2d14b3dbff409a4e597600 100644
--- a/workflow/tests/test_pool_and_psuedoreplicate.py
+++ b/workflow/tests/test_pool_and_psuedoreplicate.py
@@ -63,7 +63,7 @@ def test_check_controls_single(design_experiment_3):
 
 @pytest.mark.unit
 def test_single_rep(design_experiment_2):
-    sys.argv[1](['--design', design_experiment_2])
+    sys.argv[1]([--design, design_experiment_2])
     single_rep = pool_and_psuedoreplicate.main()