diff --git a/Changelog b/Changelog
--- a/Changelog
+++ b/Changelog
@@ -1,3 +1,9 @@
+2.0.6
+	- Adding Ord instance. [#41](https://github.com/kazu-yamamoto/dns/pull/41)
+	- Adding DNSSEC-related RRTYPEs [#40](https://github.com/kazu-yamamoto/dns/pull/40)
+2.0.5
+	- Supporting DNS-SEC AD (authenticated data). [#38](https://github.com/kazu-yamamoto/dns/pull/38)
+	- Removing the dependency to blaze-builder.
 2.0.4
 	- Renaming a variable to fix preprocessor conflicts [#37](https://github.com/kazu-yamamoto/dns/pull/37)
 2.0.3
diff --git a/Network/DNS/Internal.hs b/Network/DNS/Internal.hs
--- a/Network/DNS/Internal.hs
+++ b/Network/DNS/Internal.hs
@@ -30,9 +30,20 @@
           | SRV
           | DNAME
           | OPT
+          | DS
+          | RRSIG
+          | NSEC
+          | DNSKEY
+          | NSEC3
+          | NSEC3PARAM
           | TLSA
+          | CDS
+          | CDNSKEY
+          | CSYNC
           | UNKNOWN Int deriving (Eq, Show, Read)
 
+-- https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-4
+--
 rrDB :: [(TYPE, Int)]
 rrDB = [
     (A,      1)
@@ -44,9 +55,18 @@
   , (TXT,   16)
   , (AAAA,  28)
   , (SRV,   33)
-  , (DNAME, 39) -- RFC 2672
+  , (DNAME, 39) -- RFC 6672
   , (OPT,   41) -- RFC 6891
-  , (TLSA,  52) -- RFC 6898
+  , (DS,    43) -- RFC 4034
+  , (RRSIG, 46) -- RFC 4034
+  , (NSEC,  47) -- RFC 4034
+  , (DNSKEY, 48) -- RFC 4034
+  , (NSEC3, 40) -- RFC 5155
+  , (NSEC3PARAM, 51) -- RFC 5155
+  , (TLSA,  52) -- RFC 6698
+  , (CDS,   59) -- RFC 7344
+  , (CDNSKEY, 60) -- RFC 7344
+  , (CSYNC, 62) -- RFC 7477
   ]
 
 data OPTTYPE = ClientSubnet
@@ -162,7 +182,7 @@
   | NotImpl
   | Refused
   | BadOpt
-  deriving (Eq, Show, Enum, Bounded)
+  deriving (Eq, Ord, Show, Enum, Bounded)
 
 ----------------------------------------------------------------
 
@@ -207,11 +227,11 @@
            | RD_OPT [OData]
            | RD_OTH ByteString
            | RD_TLSA Int Int Int ByteString
-    deriving (Eq)
+    deriving (Eq, Ord)
 
 instance Show RData where
   show (RD_NS dom) = BS.unpack dom
-  show (RD_MX prf dom) = BS.unpack dom ++ " " ++ show prf
+  show (RD_MX prf dom) = show prf ++ " " ++ BS.unpack dom
   show (RD_CNAME dom) = BS.unpack dom
   show (RD_DNAME dom) = BS.unpack dom
   show (RD_A a) = show a
@@ -227,7 +247,7 @@
 
 data OData = OD_ClientSubnet Int Int IP
            | OD_Unknown Int ByteString
-    deriving (Eq,Show)
+    deriving (Eq,Show,Ord)
 
 ----------------------------------------------------------------
 
diff --git a/dns.cabal b/dns.cabal
--- a/dns.cabal
+++ b/dns.cabal
@@ -1,5 +1,5 @@
 Name:                   dns
-Version:                2.0.5
+Version:                2.0.6
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3
diff --git a/test2/doctests.hs b/test2/doctests.hs
--- a/test2/doctests.hs
+++ b/test2/doctests.hs
@@ -5,5 +5,13 @@
 main :: IO ()
 main = doctest [
     "-XOverloadedStrings"
+  {-
+    Both 'iproute' and 'network-data' provide
+    ‘Data.IP’ package:
+      Ambiguous interface for ‘Data.IP’:
+        it was found in multiple packages: network-data-0.5.3 iproute-1.7.0
+    We ignore network-data to make tests pass.
+  -}
+  , "-ignore-package=network-data"
   , "Network/DNS.hs"
   ]