diff --git a/src/provabgs/models.py b/src/provabgs/models.py
index 6f86acc..80cb4ca 100644
--- a/src/provabgs/models.py
+++ b/src/provabgs/models.py
@@ -13,7 +13,8 @@
 import scipy.interpolate as Interp
 # --- astropy --- 
 from astropy import units as U
-from astropy.cosmology import Cosmology, Planck13
+from astropy.cosmology.core import Cosmology
+from astropy.cosmology import Planck13
 # --- gqp_mc --- 
 from . import util as UT