diff --git a/lightseq/inference/model/decoder.cc.cu b/lightseq/inference/model/decoder.cc.cu
index 07c1f9a3..a24127f3 100644
--- a/lightseq/inference/model/decoder.cc.cu
+++ b/lightseq/inference/model/decoder.cc.cu
@@ -255,7 +255,7 @@ std::string Decoder<OpType_>::check() {
   if (_tw._multilg_type != 0 && _p_d_lang_id == nullptr) {
     return "lang id should not be null when multilg";
   }
-  if (_tw._max_step > 1024) {
+  if (_tw._max_step > 1026) {
     return "max_step should not greater than 1024";
   }
   return "";
diff --git a/lightseq/inference/server/model_config.h b/lightseq/inference/server/model_config.h
index ded5bf55..36ba2810 100644
--- a/lightseq/inference/server/model_config.h
+++ b/lightseq/inference/server/model_config.h
@@ -40,8 +40,8 @@ using CorrelationID = uint64_t;
 using DimsList = ::google::protobuf::RepeatedField<::google::protobuf::int64>;
 
 /// The type for the metric_tags map.
-using MetricTagsMap = ::google::protobuf::Map<::google::protobuf::string,
-                                              ::google::protobuf::string>;
+using MetricTagsMap = ::google::protobuf::Map<::std::string,
+                                              ::std::string>;
 
 /// The type from platform name to the backend configuration for that
 /// platform.