diff --git a/hiro_models/one_qubit_model.py b/hiro_models/one_qubit_model.py
index 21cebec..a6af1d9 100644
--- a/hiro_models/one_qubit_model.py
+++ b/hiro_models/one_qubit_model.py
@@ -34,7 +34,7 @@ from hops.util.truncation_schemes import (
 import stocproc as sp
 
 from beartype import beartype
-from utility import StocProcTolerances
+from .utility import StocProcTolerances
 from .model_base import Model
 import scipy.special
 import hopsflow