diff --git a/src/pkg/net/protoconn_test.go b/src/pkg/net/protoconn_test.go
index 5cdceb7721c..f249372f392 100644
--- a/src/pkg/net/protoconn_test.go
+++ b/src/pkg/net/protoconn_test.go
@@ -13,6 +13,101 @@ import (
 	"time"
 )
 
+var condErrorf = func() func(*testing.T, string, ...interface{}) {
+	// A few APIs are not implemented yet on both Plan 9 and Windows.
+	switch runtime.GOOS {
+	case "plan9", "windows":
+		return (*testing.T).Logf
+	}
+	return (*testing.T).Errorf
+}()
+
+func TestTCPListenerSpecificMethods(t *testing.T) {
+	la, err := net.ResolveTCPAddr("tcp4", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("net.ResolveTCPAddr failed: %v", err)
+	}
+	ln, err := net.ListenTCP("tcp4", la)
+	if err != nil {
+		t.Fatalf("net.ListenTCP failed: %v", err)
+	}
+	ln.Addr()
+	ln.SetDeadline(time.Now().Add(30 * time.Nanosecond))
+	defer ln.Close()
+
+	if c, err := ln.Accept(); err != nil {
+		if !err.(net.Error).Timeout() {
+			t.Errorf("net.TCPListener.Accept failed: %v", err)
+			return
+		}
+	} else {
+		c.Close()
+	}
+	if c, err := ln.AcceptTCP(); err != nil {
+		if !err.(net.Error).Timeout() {
+			t.Errorf("net.TCPListener.AcceptTCP failed: %v", err)
+			return
+		}
+	} else {
+		c.Close()
+	}
+
+	if f, err := ln.File(); err != nil {
+		condErrorf(t, "net.TCPListener.File failed: %v", err)
+		return
+	} else {
+		f.Close()
+	}
+}
+
+func TestTCPConnSpecificMethods(t *testing.T) {
+	la, err := net.ResolveTCPAddr("tcp4", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("net.ResolveTCPAddr failed: %v", err)
+	}
+	ln, err := net.ListenTCP("tcp4", la)
+	if err != nil {
+		t.Fatalf("net.ListenTCP failed: %v", err)
+	}
+	ln.Addr()
+	defer ln.Close()
+
+	done := make(chan int)
+	go transponder(t, ln, done)
+
+	ra, err := net.ResolveTCPAddr("tcp4", ln.Addr().String())
+	if err != nil {
+		t.Errorf("net.ResolveTCPAddr failed: %v", err)
+		return
+	}
+	c, err := net.DialTCP("tcp4", nil, ra)
+	if err != nil {
+		t.Errorf("net.DialTCP failed: %v", err)
+		return
+	}
+	c.SetKeepAlive(false)
+	c.SetLinger(0)
+	c.SetNoDelay(false)
+	c.LocalAddr()
+	c.RemoteAddr()
+	c.SetDeadline(time.Now().Add(100 * time.Millisecond))
+	c.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
+	c.SetWriteDeadline(time.Now().Add(100 * time.Millisecond))
+	defer c.Close()
+
+	if _, err := c.Write([]byte("TCPCONN TEST")); err != nil {
+		t.Errorf("net.TCPConn.Write failed: %v", err)
+		return
+	}
+	rb := make([]byte, 128)
+	if _, err := c.Read(rb); err != nil {
+		t.Errorf("net.TCPConn.Read failed: %v", err)
+		return
+	}
+
+	<-done
+}
+
 func TestUDPConnSpecificMethods(t *testing.T) {
 	la, err := net.ResolveUDPAddr("udp4", "127.0.0.1:0")
 	if err != nil {
@@ -22,7 +117,6 @@ func TestUDPConnSpecificMethods(t *testing.T) {
 	if err != nil {
 		t.Fatalf("net.ListenUDP failed: %v", err)
 	}
-	c.File()
 	c.LocalAddr()
 	c.RemoteAddr()
 	c.SetDeadline(time.Now().Add(100 * time.Millisecond))
@@ -33,12 +127,29 @@ func TestUDPConnSpecificMethods(t *testing.T) {
 	defer c.Close()
 
 	wb := []byte("UDPCONN TEST")
-	if _, err := c.WriteToUDP(wb, c.LocalAddr().(*net.UDPAddr)); err != nil {
-		t.Fatalf("net.UDPConn.WriteToUDP failed: %v", err)
-	}
 	rb := make([]byte, 128)
+	if _, err := c.WriteToUDP(wb, c.LocalAddr().(*net.UDPAddr)); err != nil {
+		t.Errorf("net.UDPConn.WriteToUDP failed: %v", err)
+		return
+	}
 	if _, _, err := c.ReadFromUDP(rb); err != nil {
-		t.Fatalf("net.UDPConn.ReadFromUDP failed: %v", err)
+		t.Errorf("net.UDPConn.ReadFromUDP failed: %v", err)
+		return
+	}
+	if _, _, err := c.WriteMsgUDP(wb, nil, c.LocalAddr().(*net.UDPAddr)); err != nil {
+		condErrorf(t, "net.UDPConn.WriteMsgUDP failed: %v", err)
+		return
+	}
+	if _, _, _, _, err := c.ReadMsgUDP(rb, nil); err != nil {
+		condErrorf(t, "net.UDPConn.ReadMsgUDP failed: %v", err)
+		return
+	}
+
+	if f, err := c.File(); err != nil {
+		condErrorf(t, "net.UDPConn.File failed: %v", err)
+		return
+	} else {
+		f.Close()
 	}
 }
 
@@ -61,7 +172,6 @@ func TestIPConnSpecificMethods(t *testing.T) {
 	if err != nil {
 		t.Fatalf("net.ListenIP failed: %v", err)
 	}
-	c.File()
 	c.LocalAddr()
 	c.RemoteAddr()
 	c.SetDeadline(time.Now().Add(100 * time.Millisecond))
@@ -73,16 +183,79 @@ func TestIPConnSpecificMethods(t *testing.T) {
 
 	id := os.Getpid() & 0xffff
 	wb := newICMPEchoRequest(id, 1, 128, []byte("IPCONN TEST "))
-	if _, err := c.WriteToIP(wb, c.LocalAddr().(*net.IPAddr)); err != nil {
-		t.Fatalf("net.IPConn.WriteToIP failed: %v", err)
-	}
 	rb := make([]byte, 20+128)
+	if _, err := c.WriteToIP(wb, c.LocalAddr().(*net.IPAddr)); err != nil {
+		t.Errorf("net.IPConn.WriteToIP failed: %v", err)
+		return
+	}
 	if _, _, err := c.ReadFromIP(rb); err != nil {
-		t.Fatalf("net.IPConn.ReadFromIP failed: %v", err)
+		t.Errorf("net.IPConn.ReadFromIP failed: %v", err)
+		return
+	}
+	if _, _, err := c.WriteMsgIP(wb, nil, c.LocalAddr().(*net.IPAddr)); err != nil {
+		condErrorf(t, "net.UDPConn.WriteMsgIP failed: %v", err)
+		return
+	}
+	if _, _, _, _, err := c.ReadMsgIP(rb, nil); err != nil {
+		condErrorf(t, "net.UDPConn.ReadMsgIP failed: %v", err)
+		return
+	}
+
+	if f, err := c.File(); err != nil {
+		condErrorf(t, "net.IPConn.File failed: %v", err)
+		return
+	} else {
+		f.Close()
+	}
+}
+
+func TestUnixListenerSpecificMethods(t *testing.T) {
+	switch runtime.GOOS {
+	case "plan9", "windows":
+		t.Logf("skipping read test on %q", runtime.GOOS)
+		return
+	}
+
+	p := "/tmp/gotest.net"
+	os.Remove(p)
+	la, err := net.ResolveUnixAddr("unix", p)
+	if err != nil {
+		t.Fatalf("net.ResolveUnixAddr failed: %v", err)
+	}
+	ln, err := net.ListenUnix("unix", la)
+	if err != nil {
+		t.Fatalf("net.ListenUnix failed: %v", err)
+	}
+	ln.Addr()
+	ln.SetDeadline(time.Now().Add(30 * time.Nanosecond))
+	defer ln.Close()
+	defer os.Remove(p)
+
+	if c, err := ln.Accept(); err != nil {
+		if !err.(net.Error).Timeout() {
+			t.Errorf("net.TCPListener.AcceptTCP failed: %v", err)
+			return
+		}
+	} else {
+		c.Close()
+	}
+	if c, err := ln.AcceptUnix(); err != nil {
+		if !err.(net.Error).Timeout() {
+			t.Errorf("net.TCPListener.AcceptTCP failed: %v", err)
+			return
+		}
+	} else {
+		c.Close()
+	}
+
+	if f, err := ln.File(); err != nil {
+		t.Errorf("net.UnixListener.File failed: %v", err)
+		return
+	} else {
+		f.Close()
 	}
 }
 
-// TODO: Find out the use case of ListenUnixgram, I have no idea.
 func TestUnixConnSpecificMethods(t *testing.T) {
 	switch runtime.GOOS {
 	case "plan9", "windows":
@@ -102,7 +275,6 @@ func TestUnixConnSpecificMethods(t *testing.T) {
 	if err != nil {
 		t.Fatalf("net.DialUnix failed: %v", err)
 	}
-	c1.File()
 	c1.LocalAddr()
 	c1.RemoteAddr()
 	c1.SetDeadline(time.Now().Add(100 * time.Millisecond))
@@ -115,13 +287,14 @@ func TestUnixConnSpecificMethods(t *testing.T) {
 
 	a2, err := net.ResolveUnixAddr("unixgram", p2)
 	if err != nil {
-		t.Fatalf("net.ResolveUnixAddr failed: %v", err)
+		t.Errorf("net.ResolveUnixAddr failed: %v", err)
+		return
 	}
 	c2, err := net.DialUnix("unixgram", a2, nil)
 	if err != nil {
-		t.Fatalf("net.DialUnix failed: %v", err)
+		t.Errorf("net.DialUnix failed: %v", err)
+		return
 	}
-	c2.File()
 	c2.LocalAddr()
 	c2.RemoteAddr()
 	c2.SetDeadline(time.Now().Add(100 * time.Millisecond))
@@ -133,19 +306,33 @@ func TestUnixConnSpecificMethods(t *testing.T) {
 	defer os.Remove(p2)
 
 	wb := []byte("UNIXCONN TEST")
-	if _, _, err := c1.WriteMsgUnix(wb, nil, a2); err != nil {
-		t.Fatalf("net.UnixConn.WriteMsgUnix failed: %v", err)
-	}
+	rb1 := make([]byte, 128)
 	rb2 := make([]byte, 128)
+	if _, _, err := c1.WriteMsgUnix(wb, nil, a2); err != nil {
+		t.Errorf("net.UnixConn.WriteMsgUnix failed: %v", err)
+		return
+	}
 	if _, _, _, _, err := c2.ReadMsgUnix(rb2, nil); err != nil {
-		t.Fatalf("net.UnixConn.ReadMsgUnix failed: %v", err)
+		t.Errorf("net.UnixConn.ReadMsgUnix failed: %v", err)
+		return
 	}
 	if _, err := c2.WriteToUnix(wb, a1); err != nil {
-		t.Fatalf("net.UnixConn.WriteToUnix failed: %v", err)
+		t.Errorf("net.UnixConn.WriteToUnix failed: %v", err)
+		return
 	}
-	rb1 := make([]byte, 128)
 	if _, _, err := c1.ReadFromUnix(rb1); err != nil {
-		t.Fatalf("net.UnixConn.ReadFromUnix failed: %v", err)
+		t.Errorf("net.UnixConn.ReadFromUnix failed: %v", err)
+		return
+	}
+
+	// TODO: http://golang.org/issue/3875
+	net.ListenUnixgram("unixgram", nil)
+
+	if f, err := c1.File(); err != nil {
+		t.Errorf("net.UnixConn.File failed: %v", err)
+		return
+	} else {
+		f.Close()
 	}
 }