diff --git a/server.go b/server.go
index d3a8073d9..52c1bb72e 100644
--- a/server.go
+++ b/server.go
@@ -115,12 +115,14 @@ func CustomCodec(codec Codec) ServerOption {
 	}
 }
 
+// RPCCompressor returns a ServerOption that sets a compressor for outbound message.
 func RPCCompressor(cp Compressor) ServerOption {
 	return func(o *options) {
 		o.cp = cp
 	}
 }
 
+// RPCDecompressor returns a ServerOption that sets a decompressor for inbound message.
 func RPCDecompressor(dc Decompressor) ServerOption {
 	return func(o *options) {
 		o.dc = dc
diff --git a/trace.go b/trace.go
index cde04fbfc..f6747e1df 100644
--- a/trace.go
+++ b/trace.go
@@ -101,9 +101,8 @@ type payload struct {
 func (p payload) String() string {
 	if p.sent {
 		return fmt.Sprintf("sent: %v", p.msg)
-	} else {
-		return fmt.Sprintf("recv: %v", p.msg)
 	}
+	return fmt.Sprintf("recv: %v", p.msg)
 }
 
 type fmtStringer struct {