diff --git a/src/brpc/policy/http_rpc_protocol.cpp b/src/brpc/policy/http_rpc_protocol.cpp
index 2587cf3f04..52fff2c9cf 100644
--- a/src/brpc/policy/http_rpc_protocol.cpp
+++ b/src/brpc/policy/http_rpc_protocol.cpp
@@ -1578,15 +1578,17 @@ void ProcessHttpRequest(InputMessageBase *msg) {
                 }
             }
         }
-        SampledRequest* sample = AskToBeSampled();
-        if (sample && !is_http2) {
-            sample->meta.set_compress_type(COMPRESS_TYPE_NONE);
-            sample->meta.set_protocol_type(PROTOCOL_HTTP);
-            sample->meta.set_attachment_size(req_body.size());
-
-            butil::EndPoint ep;
-            MakeRawHttpRequest(&sample->request, &req_header, ep, &req_body);
-            sample->submit(start_parse_us);
+        if (!is_http2) {
+            SampledRequest* sample = AskToBeSampled();
+            if (sample) {
+                sample->meta.set_compress_type(COMPRESS_TYPE_NONE);
+                sample->meta.set_protocol_type(PROTOCOL_HTTP);
+                sample->meta.set_attachment_size(req_body.size());
+
+                butil::EndPoint ep;
+                MakeRawHttpRequest(&sample->request, &req_header, ep, &req_body);
+                sample->submit(start_parse_us);
+            }
         }
     } else {
         if (imsg_guard->read_body_progressively()) {