diff --git a/m2cgen/assemblers/boosting.py b/m2cgen/assemblers/boosting.py
index 66bf8baf..b55725b0 100644
--- a/m2cgen/assemblers/boosting.py
+++ b/m2cgen/assemblers/boosting.py
@@ -17,7 +17,10 @@ class BaseBoostingAssembler(ModelAssembler):
     def __init__(self, model, estimator_params, base_score=0.0):
         super().__init__(model)
         self._all_estimator_params = estimator_params
-        self._base_score = base_score
+        if base_score is None:
+            self._base_score = 0.0
+        else:
+            self._base_score = base_score
 
         self._output_size = 1
         self._is_classification = False
@@ -141,10 +144,15 @@ def __init__(self, model):
         # Limit the number of trees that should be used for
         # assembling (if applicable).
         best_ntree_limit = getattr(model, "best_ntree_limit", None)
-
+        if model.get_params().get("base_score") is not None:
+            base_score = model.get_params()["base_score"]
+        elif model.intercept_ is not None:
+            base_score = model.intercept_[0]
+        else:
+            base_score = 0.0
         super().__init__(model,
                          trees,
-                         base_score=model.get_params()["base_score"],
+                         base_score=base_score,
                          tree_limit=best_ntree_limit)
 
     def _assemble_tree(self, tree):