diff --git a/supervised/preprocessing/preprocessing_utils.py b/supervised/preprocessing/preprocessing_utils.py
index b65adf9f..3d20c25d 100644
--- a/supervised/preprocessing/preprocessing_utils.py
+++ b/supervised/preprocessing/preprocessing_utils.py
@@ -23,7 +23,7 @@ def get_type(x):
                     "Please select one column to get its type"
                 )
         col_type = str(x.dtype)
-        
+
         data_type = PreprocessingUtils.CATEGORICAL
         if col_type.startswith("float"):
             data_type = PreprocessingUtils.CONTINOUS
diff --git a/supervised/tuner/hill_climbing.py b/supervised/tuner/hill_climbing.py
index 42227cbf..bc070915 100644
--- a/supervised/tuner/hill_climbing.py
+++ b/supervised/tuner/hill_climbing.py
@@ -60,9 +60,9 @@ def get(params, ml_task, seed=1):
             params_2 = copy.deepcopy(params)
             params_2[key_to_update] = right
 
-        if "model_architecture_json" in params_1:
+        if params_1 is not None and "model_architecture_json" in params_1:
             del params_1["model_architecture_json"]
-        if "model_architecture_json" in params_2:
+        if params_2 is not None and "model_architecture_json" in params_2:
             del params_2["model_architecture_json"]
 
         return [params_1, params_2]