diff --git a/paddle/gserver/layers/MKLDNNLRNLayer.cpp b/paddle/gserver/layers/MKLDNNLRNLayer.cpp
index 741984bb68d3881f6ac26eaca7790190ed6e572a..ac217f1363dbd0360645bbe07cd71a17cc931a79 100644
--- a/paddle/gserver/layers/MKLDNNLRNLayer.cpp
+++ b/paddle/gserver/layers/MKLDNNLRNLayer.cpp
@@ -29,7 +29,7 @@ bool MKLDNNLRNLayer::init(const LayerMap& layerMap,
   }
 
   /* the size of inputs for norm-layer is 1 */
-  CHECK_EQ(config_.inputs_size(), 1UL);
+  CHECK_EQ(config_.inputs_size(), 1);
   const NormConfig& conf = config_.inputs(0).norm_conf();
   localSize_ = conf.size();
   alpha_ = conf.scale();