diff --git a/contrib/endpoints/src/api_manager/service_control/proto.cc b/contrib/endpoints/src/api_manager/service_control/proto.cc
index aa88fb39eb25..ebe2ab291067 100644
--- a/contrib/endpoints/src/api_manager/service_control/proto.cc
+++ b/contrib/endpoints/src/api_manager/service_control/proto.cc
@@ -750,8 +750,8 @@ const char kLogFieldNameApiKey[] = "api_key";
 const char kLogFieldNameProducerProjectId[] = "producer_project_id";
 const char kLogFieldNameReferer[] = "referer";
 const char kLogFieldNameLocation[] = "location";
-const char kLogFieldNameRequestSize[] = "request_size";
-const char kLogFieldNameResponseSize[] = "response_size";
+const char kLogFieldNameRequestSize[] = "request_size_in_bytes";
+const char kLogFieldNameResponseSize[] = "response_size_in_bytes";
 const char kLogFieldNameHttpMethod[] = "http_method";
 const char kLogFieldNameHttpResponseCode[] = "http_response_code";
 const char kLogFieldNameLogMessage[] = "log_message";
diff --git a/contrib/endpoints/src/api_manager/service_control/testdata/final_report_request.golden b/contrib/endpoints/src/api_manager/service_control/testdata/final_report_request.golden
index d60b039987d1..ffc1e2531ec5 100644
--- a/contrib/endpoints/src/api_manager/service_control/testdata/final_report_request.golden
+++ b/contrib/endpoints/src/api_manager/service_control/testdata/final_report_request.golden
@@ -532,13 +532,13 @@ operations {
         }
       }
       fields {
-        key: "request_size"
+        key: "request_size_in_bytes"
         value {
           number_value: 100
         }
       }
       fields {
-        key: "response_size"
+        key: "response_size_in_bytes"
         value {
           number_value: 1048576
         }
diff --git a/contrib/endpoints/src/api_manager/service_control/testdata/report_request.golden b/contrib/endpoints/src/api_manager/service_control/testdata/report_request.golden
index faf96383418c..5c811dad1f61 100644
--- a/contrib/endpoints/src/api_manager/service_control/testdata/report_request.golden
+++ b/contrib/endpoints/src/api_manager/service_control/testdata/report_request.golden
@@ -544,13 +544,13 @@ operations {
         }
       }
       fields {
-        key: "request_size"
+        key: "request_size_in_bytes"
         value {
           number_value: 100
         }
       }
       fields {
-        key: "response_size"
+        key: "response_size_in_bytes"
         value {
           number_value: 1048576
         }
diff --git a/contrib/endpoints/src/api_manager/service_control/testdata/report_request_failed.golden b/contrib/endpoints/src/api_manager/service_control/testdata/report_request_failed.golden
index 710772cd215c..8d2d99c4b8c8 100644
--- a/contrib/endpoints/src/api_manager/service_control/testdata/report_request_failed.golden
+++ b/contrib/endpoints/src/api_manager/service_control/testdata/report_request_failed.golden
@@ -342,13 +342,13 @@ operations {
         }
       }
       fields {
-        key: "request_size"
+        key: "request_size_in_bytes"
         value {
           number_value: 100
         }
       }
       fields {
-        key: "response_size"
+        key: "response_size_in_bytes"
         value {
           number_value: 1048576
         }