diff --git a/dns/dns.go b/dns/dns.go
index 86d919f..d6b1682 100644
--- a/dns/dns.go
+++ b/dns/dns.go
@@ -104,7 +104,11 @@ type Question struct {
 
 // RR format
 // https://tools.ietf.org/html/rfc1035#section-3.2.1
-// All RRs have the same top level format shown below:
+// https://tools.ietf.org/html/rfc1035#section-4.1.3
+// The answer, authority, and additional sections all share the same
+// format: a variable number of resource records, where the number of
+// records is specified in the corresponding count field in the header.
+// Each resource record has the following format:
 //
 //                                     1  1  1  1  1  1
 //       0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
diff --git a/main.go b/main.go
index b197cc0..83846a4 100644
--- a/main.go
+++ b/main.go
@@ -25,7 +25,7 @@ import (
 )
 
 // VERSION .
-const VERSION = "0.6.2"
+const VERSION = "0.6.3"
 
 func dialerFromConf() proxy.Dialer {
 	// global forwarders in xx.conf
diff --git a/pprof.go b/pprof.go
new file mode 100644
index 0000000..75e6eac
--- /dev/null
+++ b/pprof.go
@@ -0,0 +1,12 @@
+//+build pprof
+
+package main
+
+import _ "net/http/pprof"
+import "net/http"
+
+func init() {
+	go func() {
+		http.ListenAndServe(":6060", nil)
+	}()
+}