diff --git a/paddle/gserver/evaluators/Evaluator.cpp b/paddle/gserver/evaluators/Evaluator.cpp
index 70f2da45ea18c3c4fdb2dfcae6deb373482d8116..1c202259831c380c52a34fa58a49dc09a0b32471 100644
--- a/paddle/gserver/evaluators/Evaluator.cpp
+++ b/paddle/gserver/evaluators/Evaluator.cpp
@@ -83,7 +83,7 @@ public:
     errorMat->zeroMem();
 
     if (label != nullptr) {
-      errorMat->classificationError(output, label);  // top-1 error
+      errorMat->classificationError(*output, *label);  // top-1 error
       size_t height = output->getHeight();
       size_t width = 5;  // config_.num_results();