diff --git a/pyhsmm/models.py b/pyhsmm/models.py
index ac6926a13dbddd0b7aa8f2c50272634225e08f01..f7974da2bb106302571349f855f844631eca5add 100644
--- a/pyhsmm/models.py
+++ b/pyhsmm/models.py
@@ -1247,7 +1247,7 @@ class _SeparateTransMixin(object):
         self.trans_distns = collections.defaultdict(
                 lambda: copy.deepcopy(self._trans_distn_prototype))
         self.init_state_distns = collections.defaultdict(
-                lambda: copy.deepcopy(self.init_state_distn_prototype))
+                lambda: copy.deepcopy(self._init_state_distn_prototype))
         self.trans_distns.update(dct['trans_distns'])
         self.init_state_distns.update(dct['init_state_distns'])