diff --git a/hiro_models/model_auxiliary.py b/hiro_models/model_auxiliary.py
index 051ff52..f77aec7 100644
--- a/hiro_models/model_auxiliary.py
+++ b/hiro_models/model_auxiliary.py
@@ -4,14 +4,14 @@ import json
 from typing import Any
 
 from hops.core.hierarchy_data import HIData
-from model_base import Model
+from .model_base import Model
 from hops.core.integration import HOPSSupervisor
 from contextlib import contextmanager
 from utility import JSONEncoder, object_hook
 from filelock import FileLock
 from pathlib import Path
-from one_qubit_model import QubitModel
-from two_qubit_model import TwoQubitModel
+from .one_qubit_model import QubitModel
+from .two_qubit_model import TwoQubitModel
 
 
 @contextmanager
diff --git a/hiro_models/model_base.py b/hiro_models/model_base.py
index 64bfb94..c1e36e2 100644
--- a/hiro_models/model_base.py
+++ b/hiro_models/model_base.py
@@ -50,7 +50,7 @@ class Model(ABC):
     def to_json(self):
         """Returns a json representation of the model configuration."""
 
-        return JSONEncoder.dumps(self.to_dict)
+        return JSONEncoder.dumps(self.to_dict())
 
     def __hash__(self):
         return hashlib.sha256(self.to_json().encode("utf-8")).digest().__hash__()
diff --git a/hiro_models/one_qubit_model.py b/hiro_models/one_qubit_model.py
index d7234a7..2181647 100644
--- a/hiro_models/one_qubit_model.py
+++ b/hiro_models/one_qubit_model.py
@@ -35,7 +35,7 @@ import stocproc as sp
 
 from beartype import beartype
 from utility import StocProcTolerances
-from model_base import Model
+from .model_base import Model
 import scipy.special
 import hopsflow
 
diff --git a/hiro_models/two_qubit_model.py b/hiro_models/two_qubit_model.py
index 19c5e54..31316f1 100644
--- a/hiro_models/two_qubit_model.py
+++ b/hiro_models/two_qubit_model.py
@@ -48,7 +48,7 @@ from hops.util.truncation_schemes import (
 import stocproc as sp
 from beartype import beartype
 from utility import StocProcTolerances, operator_norm
-from model_base import Model
+from .model_base import Model
 import hops.core.hierarchy_parameters as params
 
 
diff --git a/test_one_qubit_model.py b/test_one_qubit_model.py
index 3a2369b..d192333 100644
--- a/test_one_qubit_model.py
+++ b/test_one_qubit_model.py
@@ -1,6 +1,6 @@
 import pytest
 import random
-from models.one_qubit_model import *
+from hiro_models.one_qubit_model import *
 from qutip import *
 from utility import assert_serializable
 import scipy.integrate
diff --git a/test_two_qubit_model.py b/test_two_qubit_model.py
index 055e099..e07d626 100644
--- a/test_two_qubit_model.py
+++ b/test_two_qubit_model.py
@@ -1,6 +1,6 @@
 import pytest
 import random
-from models.two_qubit_model import *
+from hiro_models.two_qubit_model import *
 from qutip import *
 from utility import assert_serializable