diff --git a/snsim/tests/test_astrobj.py b/snsim/tests/test_astrobj.py
index 42498b4..2dc488e 100644
--- a/snsim/tests/test_astrobj.py
+++ b/snsim/tests/test_astrobj.py
@@ -37,7 +37,7 @@ def setup_class(self):
             "model_version": "2.4",
         }
 
-        self.SNIa_Tripp = sn_astrobj.SNIa(sim_par, relation="SALTTripp")
+        self.SNIa_Tripp = sn_astrobj.SNIa(sim_par, mag_fun="SALTTripp")
 
         self.obs = pd.DataFrame(
             {