diff --git a/sklearn/neighbors/classification.py b/sklearn/neighbors/classification.py
index 00099b541a7263..a1d678837356eb 100644
--- a/sklearn/neighbors/classification.py
+++ b/sklearn/neighbors/classification.py
@@ -391,7 +391,8 @@ def predict(self, X):
                                         for ind in neigh_ind[inliers]],
                                        dtype=object)
                 y_pred_k = np.zeros(n_samples, dtype=np.int)
-                mode = self._mode(pred_labels, weights, inliers)
+                mode = self._mode(pred_labels, weights, inliers,
+                                  is_comming_from_sparse_call=True)
                 y_pred_k[inliers] = mode
 
                 if outliers and self.outlier_label != 0:
@@ -419,11 +420,13 @@ def predict(self, X):
 
         return y_pred
 
-    def _mode(self, pred_labels, weights, inliers):
+    def _mode(self, pred_labels, weights, inliers, is_comming_from_sparse_call=None):
         if weights is None:
             mode = np.array([stats.mode(pl)[0]
                              for pl in pred_labels], dtype=np.int)
         else:
+            if is_comming_from_sparse_call:
+                import pdb; pdb.set_trace()
             mode = np.array([weighted_mode(pl, w)[0]
                              for (pl, w)
                              in zip(pred_labels, weights[inliers])],