diff --git a/include/netlink.hrl b/include/netlink.hrl
index d1b1fa5..df02e04 100644
--- a/include/netlink.hrl
+++ b/include/netlink.hrl
@@ -22,18 +22,41 @@
 -define(NETLINK_SCSITRANSPORT, 18).
 -define(NETLINK_ECRYPTFS, 19).
 
+-type flags() :: list(atom()).
+-type family() :: atom().
+-type protocol() :: atom().
+-type arphdr() :: atom().
+-type ifindex() :: non_neg_integer().
+-type resid() :: non_neg_integer().
+-type nla() :: list({atom(),term()}).
+-type ctnetlink_msg() :: {family(),non_neg_integer(),non_neg_integer(),list()}.
+-type rtnetlink_neigh() :: {family(),ifindex(),non_neg_integer(),flags(),non_neg_integer(),nla()}.
+-type rtnetlink_route() :: {family(),non_neg_integer(),non_neg_integer(),non_neg_integer(),non_neg_integer(),protocol(),non_neg_integer(),non_neg_integer(),flags(),nla()}.
+-type rtnetlink_addr() :: {family(),non_neg_integer(),flags(),non_neg_integer(),non_neg_integer(),nla()}.
+-type rtnetlink_link() :: {family(),arphdr(),non_neg_integer(),flags(),flags(),nla()}.
+-type rtnetlink_prefix() :: {family(),ifindex(),non_neg_integer(),non_neg_integer(),flags(),nla()}.
+-type rtnetlink_msg() :: rtnetlink_neigh() | rtnetlink_route() | rtnetlink_addr() | rtnetlink_link() | rtnetlink_prefix().
+
+-record(rtnetlink, {
+		  type          ::atom(),
+		  flags         ::list(atom()),
+		  seq           ::non_neg_integer(),
+		  pid           ::non_neg_integer(),
+		  msg           ::rtnetlink_msg()
+		 }).
+
 -record(ctnetlink, {
-		  type,
-		  flags,
-		  seq,
-		  pid,
-		  msg
+		  type          ::'new'|'get'|'delete'|'get_ctrzero',
+		  flags         ::flags(),
+		  seq           ::non_neg_integer(),
+		  pid           ::non_neg_integer(),
+		  msg           ::ctnetlink_msg()
 		 }).
 
 -record(ctnetlink_exp, {
-		  type,
-		  flags,
-		  seq,
-		  pid,
-		  msg
+		  type          ::'new'|'get'|'delete'|'get_ctrzero',
+		  flags         ::flags(),
+		  seq           ::non_neg_integer(),
+		  pid           ::non_neg_integer(),
+		  msg           ::ctnetlink_msg()
 		 }).
diff --git a/src/netlink.erl b/src/netlink.erl
index dbb6a77..7bd8d74 100644
--- a/src/netlink.erl
+++ b/src/netlink.erl
@@ -659,6 +659,8 @@ ipctnl_msg(SubSys, Type) ->
 sockaddr_nl(Family, Pid, Groups) ->
     sockaddr_nl({Family, Pid, Groups}).
 
+-spec sockaddr_nl({atom()|integer(),integer(),integer()}) -> binary();
+				 (binary()) -> {atom()|integer(),integer(),integer()}.
 sockaddr_nl({Family, Pid, Groups}) when is_atom(Family) ->
     sockaddr_nl({gen_socket:family(Family), Pid, Groups});
 sockaddr_nl({Family, Pid, Groups}) ->
@@ -988,6 +990,7 @@ nlmsg_ok(DataLen, MsgLen) ->
 nl_ct_dec_udp(<< _IpHdr:5/bytes, Data/binary >>) ->
 	nl_ct_dec(Data).
 
+-spec nl_ct_dec(binary()) -> [{'error',_} | #ctnetlink{} | #ctnetlink_exp{}].
 nl_ct_dec(Msg) ->
     nl_ct_dec(Msg, []).
 
@@ -1015,6 +1018,7 @@ nl_ct_dec(<< >>, Acc) ->
 nl_rt_dec_udp(<< _IpHdr:5/bytes, Data/binary >>) ->
     nl_rt_dec(Data).
 
+-spec nl_rt_dec(binary()) -> [{'error',_} | #rtnetlink{}].
 nl_rt_dec(Msg) ->
     nl_rt_dec(Msg, []).
 
@@ -1096,7 +1100,7 @@ nl_ct_enc({SubSys, MsgType, Flags, Seq, Pid, PayLoad})
   when is_atom(SubSys), is_integer(MsgType) ->
 	Data = nl_enc_payload({SubSys}, MsgType, PayLoad),
 	Type = (nfnl_subsys(SubSys) bsl 8) bor MsgType,
-	Flags0 = case MsgType of
+	Flags0 = case ipctnl_msg(SubSys, MsgType) of
 				 new -> enc_flags(nlm_new_flags, Flags);
 				 _ ->   enc_flags(nlm_get_flags, Flags)
 			 end,