diff --git a/README.markdown b/README.markdown
index c59c9f09..085a05fb 100644
--- a/README.markdown
+++ b/README.markdown
@@ -38,6 +38,7 @@ Miek Gieben  -  2010, 2011 - miek@miek.nl
 * 403{3,4,5} - DNSSEC + validation functions
 * 4255 - SSHFP
 * 4408 - SPF
+* 4509 - SHA256 Hash in DS
 * 4635 - HMAC SHA TSIG
 * 5001 - NSID 
 * 5155 - NSEC
diff --git a/edns.go b/edns.go
index 497d9431..0b19202e 100644
--- a/edns.go
+++ b/edns.go
@@ -7,9 +7,10 @@ import (
 
 // EDNS0 Options
 const (
-	OptionCodeLLQ  = 1      // not used
-	OptionCodeUL   = 2      // not used
-	OptionCodeNSID = 3      // NSID, RFC5001
+	_              = iota
+	OptionCodeLLQ           // not used
+	OptionCodeUL            // not used
+	OptionCodeNSID          // NSID, RFC5001
 	_DO            = 1 << 7 // dnssec ok
 )