diff --git a/paddle/fluid/framework/op_desc.h b/paddle/fluid/framework/op_desc.h
index 0b7162af24e7d277f2ae317a00cc4bc95d0e5d2e..f06f67dcc3d32c87e93a3df44643f71d61689faa 100644
--- a/paddle/fluid/framework/op_desc.h
+++ b/paddle/fluid/framework/op_desc.h
@@ -33,7 +33,7 @@ class OpDesc {
   OpDesc(const std::string &type, const VariableNameMap &inputs,
          const VariableNameMap &outputs, const AttributeMap &attrs);
 
-  OpDesc(const proto::OpDesc &desc, BlockDesc *block = nullptr);
+  explicit OpDesc(const proto::OpDesc &desc, BlockDesc *block = nullptr);
 
   explicit OpDesc(BlockDesc *block) : block_(block) {}