diff --git a/tests/regression_tests/mgxs_library_specific_nuclides/test.py b/tests/regression_tests/mgxs_library_specific_nuclides/test.py
index e749ca1378..9af2ce17c5 100644
--- a/tests/regression_tests/mgxs_library_specific_nuclides/test.py
+++ b/tests/regression_tests/mgxs_library_specific_nuclides/test.py
@@ -33,7 +33,7 @@ class MGXSTestHarness(PyAPITestHarness):
         self.mgxs_lib.energy_groups = energy_groups
         self.mgxs_lib.legendre_order = 3
         self.mgxs_lib.domain_type = 'material'
-        self.mgxs_lib.nuclides=['U235','Zr90','H1']
+        self.mgxs_lib.nuclides = ['U235', 'Zr90', 'H1']
         self.mgxs_lib.build_library()
 
         # Add tallies