diff --git a/unifiedbooster/gbdt.py b/unifiedbooster/gbdt.py
index 68f1033..97a9c4e 100644
--- a/unifiedbooster/gbdt.py
+++ b/unifiedbooster/gbdt.py
@@ -128,7 +128,7 @@ def fit(self, X, y, **kwargs):
                 self.classes_
             )  # for compatibility with sklearn
         if getattr(self, "model_type") == "gradientboosting":
-            setattr(self, "model").max_features *= X.shape[1] 
+            self.model.max_features = int(self.model.max_features*X.shape[1])
         return getattr(self, "model").fit(X, y, **kwargs)
 
     def predict(self, X):