diff --git a/regrank/xgboost_regrank.h b/regrank/xgboost_regrank.h
index 02a6001d3..fd6800ce4 100644
--- a/regrank/xgboost_regrank.h
+++ b/regrank/xgboost_regrank.h
@@ -29,7 +29,7 @@ namespace xgboost{
             }
             /*! \brief destructor */
             ~RegRankBoostLearner(void){
-                delete obj_;
+                if( obj_ != NULL ) delete obj_;
             }
             /*!
              * \brief a regression booter associated with training and evaluating data