diff --git a/laborious/utils/repository/minio_repository.py b/laborious/utils/repository/minio_repository.py
index df20a06..b38af69 100644
--- a/laborious/utils/repository/minio_repository.py
+++ b/laborious/utils/repository/minio_repository.py
@@ -56,7 +56,7 @@ class MinioRepository:
     def close(self):
         self.s3_client.close()
 
-    def ensure_bucket_exists(self, metadata: dict[str, Any]) -> bool:
+    def ensure_bucket_exists(self, metadata: dict[str, Any]) -> None:
         """
         Ensure the MinIO bucket exists; create it if necessary.
         """
@@ -64,13 +64,10 @@ class MinioRepository:
         try:
             self.logger.custom_info(f"Checking if bucket '{self.minio_bucket}' exists", metadata)
             self.s3_client.head_bucket(Bucket=self.minio_bucket)
-            return True
         except ClientError:
             self.logger.custom_info(f"Creating bucket '{self.minio_bucket}'", metadata)
             self.s3_client.create_bucket(Bucket=self.minio_bucket)
 
-            return True
-
     def store_dataframe_as_parquet(
         self, dataframe: DataFrame, uri: str, object_name: str, metadata: dict[str, Any]
     ):
diff --git a/laborious/utils/repository/model_repository.py b/laborious/utils/repository/model_repository.py
index 3e786c7..f9e783b 100644
--- a/laborious/utils/repository/model_repository.py
+++ b/laborious/utils/repository/model_repository.py
@@ -33,6 +33,7 @@ ARTIFACTS_PATH = './tmp/artifacts'
 TRANSFORMED_COMPRESSED_PATH = 'artifacts/training_transformer.pkl'
 PREDICTION_COMPRESSED_PATH = 'artifacts/stacking_model.pkl'
 
+INVALID_FLAVOR_MESSAGE = "Invalid flavor. Use 'sklearn' or 'pyfunc' or 'pytorch'."
 
 def force_memory_release(logger: Logger):
     gc.collect()
@@ -222,7 +223,7 @@ class MLFlowRepository:
         elif flavor == 'pytorch':
             model = mlflow.pytorch.load_model(model_uri)
         else:
-            raise ValueError("Invalid flavor. Use 'sklearn' or 'pyfunc' or 'pytorch'.")
+            raise ValueError(INVALID_FLAVOR_MESSAGE)
 
         return model
 
@@ -257,7 +258,7 @@ class MLFlowRepository:
         elif flavor == 'pytorch':
             model = mlflow.pytorch.load_model(model_uri)
         else:
-            raise ValueError("Invalid flavor. Use 'sklearn' or 'pyfunc' or 'pytorch'.")
+            raise ValueError(INVALID_FLAVOR_MESSAGE)
         return model
 
     def download_model(
@@ -628,7 +629,7 @@ class MLFlowRepository:
             # Aligns data with treated data indexes to get target variable
             aligned_data = data.loc[treated_data.index]
             aligned_series = aligned_data[target_name]
-            retrain_dataset = pd.merge(
+            retrain_dataset = pd.merge( # NOSONAR
                 treated_data, aligned_series, left_index=True, right_index=True
             )
         else:
@@ -673,7 +674,7 @@ class MLFlowRepository:
         elif flavor == 'pytorch':
             mlflow.pytorch.log_model(model, model_type)
         else:
-            raise ValueError("Invalid flavor. Use 'sklearn' or 'pyfunc' or 'pytorch'.")
+            raise ValueError(INVALID_FLAVOR_MESSAGE)
 
     def create_new_experiment(
         self,
@@ -980,7 +981,7 @@ class MLFlowRepository:
 
                 # predict_data.to_csv(
                 #     f"tmp/predicted_data_{model_name}.csv", index=True)
-                predict_data.columns = ['prediction']
+                predict_data.columns = pd.Index(['prediction'])
 
             else:
                 predict_data = pd.DataFrame(predict_data, columns=['prediction'])