diff --git a/etcdserver/apply.go b/etcdserver/apply.go
index 42b1caf65..f43904dea 100644
--- a/etcdserver/apply.go
+++ b/etcdserver/apply.go
@@ -181,7 +181,7 @@ func (a *applierV3backend) Put(txn mvcc.TxnWrite, p *pb.PutRequest) (resp *pb.Pu
 	trace = traceutil.New("put",
 		a.s.getLogger(),
 		traceutil.Field{Key: "key", Value: string(p.Key)},
-		traceutil.Field{Key: "req_size", Value: proto.Size(p)},
+		traceutil.Field{Key: "req_size", Value: p.Size()},
 	)
 	val, leaseID := p.Value, lease.LeaseID(p.Lease)
 	if txn == nil {
diff --git a/etcdserver/util.go b/etcdserver/util.go
index 977bd68da..bd80202a6 100644
--- a/etcdserver/util.go
+++ b/etcdserver/util.go
@@ -143,7 +143,7 @@ func warnOfExpensiveReadOnlyTxnRequest(lg *zap.Logger, warningApplyDuration time
 				// only range responses should be in a read only txn request
 			}
 		}
-		resp = fmt.Sprintf("responses:<%s> size:%d", strings.Join(resps, " "), proto.Size(txnResponse))
+		resp = fmt.Sprintf("responses:<%s> size:%d", strings.Join(resps, " "), txnResponse.Size())
 	}
 	warnOfExpensiveGenericRequest(lg, warningApplyDuration, now, reqStringer, "read-only range ", resp, err)
 }
@@ -151,7 +151,7 @@ func warnOfExpensiveReadOnlyTxnRequest(lg *zap.Logger, warningApplyDuration time
 func warnOfExpensiveReadOnlyRangeRequest(lg *zap.Logger, warningApplyDuration time.Duration, now time.Time, reqStringer fmt.Stringer, rangeResponse *pb.RangeResponse, err error) {
 	var resp string
 	if !isNil(rangeResponse) {
-		resp = fmt.Sprintf("range_response_count:%d size:%d", len(rangeResponse.Kvs), proto.Size(rangeResponse))
+		resp = fmt.Sprintf("range_response_count:%d size:%d", len(rangeResponse.Kvs), rangeResponse.Size())
 	}
 	warnOfExpensiveGenericRequest(lg, warningApplyDuration, now, reqStringer, "read-only range ", resp, err)
 }