diff --git a/paddle/gserver/layers/CostLayer.cpp b/paddle/gserver/layers/CostLayer.cpp
index 91a742422e2f2efc1a0f4b6ec55963a3e9bdc254..7f648070f27a2f155beb06c76971dd690fca7e9c 100644
--- a/paddle/gserver/layers/CostLayer.cpp
+++ b/paddle/gserver/layers/CostLayer.cpp
@@ -644,7 +644,7 @@ void HuberRegressionLoss::backwardImp(Matrix& output,
     if (std::abs(a) <= delta_)
       grad[i] += -a;
     else
-      grad[i] += a > 0 ? delta_ : -delta_;
+      grad[i] += a > 0 ? -delta_ : delta_;
   }
   if (useGpu_) outputG.copyFrom(grad, numSamples);
 }