diff --git a/darts/tests/models/forecasting/test_backtesting.py b/darts/tests/models/forecasting/test_backtesting.py
index 3c4013b954..0f6336043a 100644
--- a/darts/tests/models/forecasting/test_backtesting.py
+++ b/darts/tests/models/forecasting/test_backtesting.py
@@ -14,8 +14,10 @@
     ARIMA,
     FFT,
     ExponentialSmoothing,
+    LinearRegressionModel,
     NaiveDrift,
     NaiveSeasonal,
+    RandomForest,
     Theta,
 )
 from darts.tests.conftest import TORCH_AVAILABLE, tfm_kwargs
@@ -29,12 +31,7 @@
 
 
 if TORCH_AVAILABLE:
-    from darts.models import (
-        BlockRNNModel,
-        LinearRegressionModel,
-        RandomForest,
-        TCNModel,
-    )
+    from darts.models import BlockRNNModel, TCNModel
 
 
 def get_dummy_series(
diff --git a/examples/20-RegressionModel-examples.ipynb b/examples/20-RegressionModel-examples.ipynb
index 30a84de818..bf53cdc205 100644
--- a/examples/20-RegressionModel-examples.ipynb
+++ b/examples/20-RegressionModel-examples.ipynb
@@ -976,7 +976,7 @@
     "        self.weights = weights\n",
     "        self.norm_coef = sum(weights)\n",
     "\n",
-    "    def fit(self, X: np.ndarray, y: np.ndarray):\n",
+    "    def fit(self, X: np.ndarray, y: np.ndarray, *args, **kwargs):\n",
     "        return self\n",
     "\n",
     "    def predict(self, X: np.ndarray):\n",