diff --git a/sklearn/ensemble/weight_boosting.py b/sklearn/ensemble/weight_boosting.py
index b75e607b5b463..f13d16befb140 100644
--- a/sklearn/ensemble/weight_boosting.py
+++ b/sklearn/ensemble/weight_boosting.py
@@ -26,7 +26,6 @@
 from abc import ABCMeta, abstractmethod
 
 import numpy as np
-from numpy.core.umath_tests import inner1d
 
 from .base import BaseEnsemble
 from ..base import ClassifierMixin, RegressorMixin, is_regressor, is_classifier
@@ -522,8 +521,8 @@ def _boost_real(self, iboost, X, y, sample_weight, random_state):
 
         # Boost weight using multi-class AdaBoost SAMME.R alg
         estimator_weight = (-1. * self.learning_rate
-                                * (((n_classes - 1.) / n_classes) *
-                                   inner1d(y_coding, np.log(y_predict_proba))))
+                            * ((n_classes - 1.) / n_classes)
+                            * (y_coding * np.log(y_predict_proba)).sum(axis=1))
 
         # Only boost the weights if it will fit again
         if not iboost == self.n_estimators - 1: