diff --git a/proto/api_v2/query.proto b/proto/api_v2/query.proto
index 43c4969..7c69b3a 100644
--- a/proto/api_v2/query.proto
+++ b/proto/api_v2/query.proto
@@ -42,11 +42,13 @@ message GetTraceRequest {
   ];
   // Optional. The start time to search trace ID.
   google.protobuf.Timestamp start_time = 2 [
-    (gogoproto.stdtime) = true
+    (gogoproto.stdtime) = true,
+    (gogoproto.nullable) = false
   ];
   // Optional. The end time to search trace ID.
   google.protobuf.Timestamp end_time = 3 [
-    (gogoproto.stdtime) = true
+    (gogoproto.stdtime) = true,
+    (gogoproto.nullable) = false
   ];
 }
 
diff --git a/proto/api_v3/query_service.proto b/proto/api_v3/query_service.proto
index 61feed0..ebf125e 100644
--- a/proto/api_v3/query_service.proto
+++ b/proto/api_v3/query_service.proto
@@ -30,11 +30,13 @@ message GetTraceRequest {
   string trace_id = 1;
   // Optional. The start time to search trace ID.
   google.protobuf.Timestamp start_time = 2 [
-    (gogoproto.stdtime) = true
+    (gogoproto.stdtime) = true,
+    (gogoproto.nullable) = false
   ];
   // Optional. The end time to search trace ID.
   google.protobuf.Timestamp end_time = 3 [
-    (gogoproto.stdtime) = true
+    (gogoproto.stdtime) = true,
+    (gogoproto.nullable) = false
   ];
 }