diff --git a/conn.go b/conn.go
index 8b8ac7a8..ac1e56f1 100644
--- a/conn.go
+++ b/conn.go
@@ -57,6 +57,8 @@ type Conn struct {
 	logger             Logger
 	mr                 msgReader
 	fp                 *fastpath
+	pgsql_af_inet      byte
+	pgsql_af_inet6     byte
 }
 
 type PreparedStatement struct {
@@ -222,6 +224,11 @@ func (c *Conn) connect(config ConnConfig, network, address string, tlsConfig *tl
 				return err
 			}
 
+			err = c.loadInetConstants()
+			if err != nil {
+				return err
+			}
+
 			return nil
 		default:
 			if err = c.processContextFreeMsg(t, r); err != nil {
@@ -254,6 +261,23 @@ func (c *Conn) loadPgTypes() error {
 	return rows.Err()
 }
 
+// Family is needed for binary encoding of inet/cidr. The constant is based on
+// the server's definition of AF_INET. In theory, this could differ between
+// platforms, so request an IPv4 and an IPv6 inet and get the family from that.
+func (c *Conn) loadInetConstants() error {
+	var ipv4, ipv6 []byte
+
+	err := c.QueryRow("select '127.0.0.1'::inet, '1::'::inet").Scan(&ipv4, &ipv6)
+	if err != nil {
+		return err
+	}
+
+	c.pgsql_af_inet = ipv4[0]
+	c.pgsql_af_inet6 = ipv6[0]
+
+	return nil
+}
+
 // Close closes a connection. It is safe to call Close on a already closed
 // connection.
 func (c *Conn) Close() (err error) {
@@ -261,7 +285,7 @@ func (c *Conn) Close() (err error) {
 		return nil
 	}
 
-	wbuf := newWriteBuf(c.wbuf[0:0], 'X')
+	wbuf := newWriteBuf(c, 'X')
 	wbuf.closeMsg()
 
 	_, err = c.conn.Write(wbuf.buf)
@@ -442,7 +466,7 @@ func (c *Conn) Prepare(name, sql string) (ps *PreparedStatement, err error) {
 	}()
 
 	// parse
-	wbuf := newWriteBuf(c.wbuf[0:0], 'P')
+	wbuf := newWriteBuf(c, 'P')
 	wbuf.WriteCString(name)
 	wbuf.WriteCString(sql)
 	wbuf.WriteInt16(0)
@@ -509,7 +533,7 @@ func (c *Conn) Deallocate(name string) (err error) {
 	delete(c.preparedStatements, name)
 
 	// close
-	wbuf := newWriteBuf(c.wbuf[0:0], 'C')
+	wbuf := newWriteBuf(c, 'C')
 	wbuf.WriteByte('S')
 	wbuf.WriteCString(name)
 
@@ -667,7 +691,7 @@ func (c *Conn) sendQuery(sql string, arguments ...interface{}) (err error) {
 
 func (c *Conn) sendSimpleQuery(sql string, args ...interface{}) error {
 	if len(args) == 0 {
-		wbuf := newWriteBuf(c.wbuf[0:0], 'Q')
+		wbuf := newWriteBuf(c, 'Q')
 		wbuf.WriteCString(sql)
 		wbuf.closeMsg()
 
@@ -694,7 +718,7 @@ func (c *Conn) sendPreparedQuery(ps *PreparedStatement, arguments ...interface{}
 	}
 
 	// bind
-	wbuf := newWriteBuf(c.wbuf[0:0], 'B')
+	wbuf := newWriteBuf(c, 'B')
 	wbuf.WriteByte(0)
 	wbuf.WriteCString(ps.Name)
 
@@ -707,7 +731,7 @@ func (c *Conn) sendPreparedQuery(ps *PreparedStatement, arguments ...interface{}
 			wbuf.WriteInt16(TextFormatCode)
 		default:
 			switch oid {
-			case BoolOid, ByteaOid, Int2Oid, Int4Oid, Int8Oid, Float4Oid, Float8Oid, TimestampTzOid, TimestampTzArrayOid, TimestampOid, TimestampArrayOid, BoolArrayOid, Int2ArrayOid, Int4ArrayOid, Int8ArrayOid, Float4ArrayOid, Float8ArrayOid, TextArrayOid, VarcharArrayOid, OidOid:
+			case BoolOid, ByteaOid, Int2Oid, Int4Oid, Int8Oid, Float4Oid, Float8Oid, TimestampTzOid, TimestampTzArrayOid, TimestampOid, TimestampArrayOid, BoolArrayOid, Int2ArrayOid, Int4ArrayOid, Int8ArrayOid, Float4ArrayOid, Float8ArrayOid, TextArrayOid, VarcharArrayOid, OidOid, InetOid, CidrOid:
 				wbuf.WriteInt16(BinaryFormatCode)
 			default:
 				wbuf.WriteInt16(TextFormatCode)
@@ -1050,7 +1074,7 @@ func (c *Conn) txStartupMessage(msg *startupMessage) error {
 }
 
 func (c *Conn) txPasswordMessage(password string) (err error) {
-	wbuf := newWriteBuf(c.wbuf[0:0], 'p')
+	wbuf := newWriteBuf(c, 'p')
 	wbuf.WriteCString(password)
 	wbuf.closeMsg()
 
diff --git a/fastpath.go b/fastpath.go
index 5eee1ea1..8814e559 100644
--- a/fastpath.go
+++ b/fastpath.go
@@ -50,11 +50,11 @@ func fpInt64Arg(n int64) fpArg {
 }
 
 func (f *fastpath) Call(oid Oid, args []fpArg) (res []byte, err error) {
-	wbuf := newWriteBuf(f.cn.wbuf[:0], 'F') // function call
-	wbuf.WriteInt32(int32(oid))             // function object id
-	wbuf.WriteInt16(1)                      // # of argument format codes
-	wbuf.WriteInt16(1)                      // format code: binary
-	wbuf.WriteInt16(int16(len(args)))       // # of arguments
+	wbuf := newWriteBuf(f.cn, 'F')    // function call
+	wbuf.WriteInt32(int32(oid))       // function object id
+	wbuf.WriteInt16(1)                // # of argument format codes
+	wbuf.WriteInt16(1)                // format code: binary
+	wbuf.WriteInt16(int16(len(args))) // # of arguments
 	for _, arg := range args {
 		wbuf.WriteInt32(int32(len(arg))) // length of argument
 		wbuf.WriteBytes(arg)             // argument value
diff --git a/messages.go b/messages.go
index 16d7301e..7cc244c8 100644
--- a/messages.go
+++ b/messages.go
@@ -89,9 +89,9 @@ func (self PgError) Error() string {
 	return self.Severity + ": " + self.Message + " (SQLSTATE " + self.Code + ")"
 }
 
-func newWriteBuf(buf []byte, t byte) *WriteBuf {
-	buf = append(buf, t, 0, 0, 0, 0)
-	return &WriteBuf{buf: buf, sizeIdx: 1}
+func newWriteBuf(c *Conn, t byte) *WriteBuf {
+	buf := append(c.wbuf[0:0], t, 0, 0, 0, 0)
+	return &WriteBuf{buf: buf, sizeIdx: 1, conn: c}
 }
 
 // WrifeBuf is used build messages to send to the PostgreSQL server. It is used
@@ -99,6 +99,7 @@ func newWriteBuf(buf []byte, t byte) *WriteBuf {
 type WriteBuf struct {
 	buf     []byte
 	sizeIdx int
+	conn    *Conn
 }
 
 func (wb *WriteBuf) startMsg(t byte) {
diff --git a/query_test.go b/query_test.go
index b9e80f8c..206b8a82 100644
--- a/query_test.go
+++ b/query_test.go
@@ -422,8 +422,8 @@ func TestQueryRowUnknownType(t *testing.T) {
 	conn := mustConnect(t, *defaultConnConfig)
 	defer closeConn(t, conn)
 
-	sql := "select $1::inet"
-	expected := "127.0.0.1"
+	sql := "select $1::point"
+	expected := "(1,0)"
 	var actual string
 
 	err := conn.QueryRow(sql, expected).Scan(&actual)
diff --git a/values.go b/values.go
index 22797d81..e1c5cd2c 100644
--- a/values.go
+++ b/values.go
@@ -54,21 +54,23 @@ var DefaultTypeFormats map[string]int16
 
 func init() {
 	DefaultTypeFormats = make(map[string]int16)
+	DefaultTypeFormats["_bool"] = BinaryFormatCode
 	DefaultTypeFormats["_float4"] = BinaryFormatCode
 	DefaultTypeFormats["_float8"] = BinaryFormatCode
-	DefaultTypeFormats["_bool"] = BinaryFormatCode
 	DefaultTypeFormats["_int2"] = BinaryFormatCode
 	DefaultTypeFormats["_int4"] = BinaryFormatCode
 	DefaultTypeFormats["_int8"] = BinaryFormatCode
 	DefaultTypeFormats["_text"] = BinaryFormatCode
-	DefaultTypeFormats["_varchar"] = BinaryFormatCode
 	DefaultTypeFormats["_timestamp"] = BinaryFormatCode
 	DefaultTypeFormats["_timestamptz"] = BinaryFormatCode
+	DefaultTypeFormats["_varchar"] = BinaryFormatCode
 	DefaultTypeFormats["bool"] = BinaryFormatCode
 	DefaultTypeFormats["bytea"] = BinaryFormatCode
+	DefaultTypeFormats["cidr"] = BinaryFormatCode
 	DefaultTypeFormats["date"] = BinaryFormatCode
 	DefaultTypeFormats["float4"] = BinaryFormatCode
 	DefaultTypeFormats["float8"] = BinaryFormatCode
+	DefaultTypeFormats["inet"] = BinaryFormatCode
 	DefaultTypeFormats["int2"] = BinaryFormatCode
 	DefaultTypeFormats["int4"] = BinaryFormatCode
 	DefaultTypeFormats["int8"] = BinaryFormatCode
@@ -1112,41 +1114,32 @@ func decodeInet(vr *ValueReader) net.IPNet {
 		return zero
 	}
 
+	if vr.Type().FormatCode != BinaryFormatCode {
+		vr.Fatal(ProtocolError(fmt.Sprintf("Unknown field description format code: %v", vr.Type().FormatCode)))
+		return zero
+	}
+
 	pgType := vr.Type()
+	if vr.Len() != 8 && vr.Len() != 20 {
+		vr.Fatal(ProtocolError(fmt.Sprintf("Received an invalid size for a %s: %d", pgType.Name, vr.Len())))
+		return zero
+	}
+
 	if pgType.DataType != InetOid && pgType.DataType != CidrOid {
-		vr.Fatal(ProtocolError(fmt.Sprintf("Cannot decode oid %v into %s", pgType.DataType, vr.Type().Name)))
+		vr.Fatal(ProtocolError(fmt.Sprintf("Cannot decode oid %v into %s", pgType.DataType, pgType.Name)))
 		return zero
 	}
 
-	s := vr.ReadString(vr.Len())
-	hasNetmask := strings.ContainsRune(s, '/')
-	if !hasNetmask {
-		isIpv6 := strings.ContainsRune(s, ':')
-		if isIpv6 {
-			s += "/128"
-		} else {
-			s += "/32"
-		}
-	}
+	vr.ReadByte() // ignore family
+	bits := vr.ReadByte()
+	vr.ReadByte() // ignore is_cidr
+	addressLength := vr.ReadByte()
 
-	_, ipnet, err := net.ParseCIDR(s)
-	if err != nil {
-		vr.Fatal(err)
-		return zero
-	}
-
-	// if vr.Type().FormatCode != BinaryFormatCode {
-	// 	vr.Fatal(ProtocolError(fmt.Sprintf("Unknown field description format code: %v", vr.Type().FormatCode)))
-	// 	return zero
-	// }
-
-	// if vr.Len() != 4 {
-	// 	vr.Fatal(ProtocolError(fmt.Sprintf("Received an invalid size for an float4: %d", vr.Len())))
-	// 	return zero
-	// }
-
-	return *ipnet
+	var ipnet net.IPNet
+	ipnet.IP = vr.ReadBytes(int32(addressLength))
+	ipnet.Mask = net.CIDRMask(int(bits), int(addressLength)*8)
 
+	return ipnet
 }
 
 func encodeInet(w *WriteBuf, value interface{}) error {
@@ -1159,10 +1152,26 @@ func encodeInet(w *WriteBuf, value interface{}) error {
 		return fmt.Errorf("Expected net.IPNet, received %T %v", value, value)
 	}
 
-	s := ipnet.String()
+	var size int32
+	var family byte
+	switch len(ipnet.IP) {
+	case net.IPv4len:
+		size = 8
+		family = w.conn.pgsql_af_inet
+	case net.IPv6len:
+		size = 20
+		family = w.conn.pgsql_af_inet6
+	default:
+		return fmt.Errorf("Unexpected IP length: %v", len(ipnet.IP))
+	}
 
-	w.WriteInt32(int32(len(s)))
-	w.WriteBytes([]byte(s))
+	w.WriteInt32(size)
+	w.WriteByte(family)
+	ones, _ := ipnet.Mask.Size()
+	w.WriteByte(byte(ones))
+	w.WriteByte(0) // is_cidr is ignored on server
+	w.WriteByte(byte(len(ipnet.IP)))
+	w.WriteBytes(ipnet.IP)
 
 	return nil
 }
diff --git a/values_test.go b/values_test.go
index bf866fef..f191d479 100644
--- a/values_test.go
+++ b/values_test.go
@@ -137,6 +137,7 @@ func TestInetCidrTranscode(t *testing.T) {
 		err := conn.QueryRow(tt.sql, tt.value).Scan(&actual)
 		if err != nil {
 			t.Errorf("%d. Unexpected failure: %v (sql -> %v, value -> %v)", i, err, tt.sql, tt.value)
+			continue
 		}
 
 		if actual.String() != tt.value.String() {