diff --git a/ipv6/icmp_test.go b/ipv6/icmp_test.go
index d0c8089c..e192d6d8 100644
--- a/ipv6/icmp_test.go
+++ b/ipv6/icmp_test.go
@@ -35,7 +35,7 @@ func TestICMPString(t *testing.T) {
 func TestICMPFilter(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 
 	var f ipv6.ICMPFilter
@@ -62,7 +62,7 @@ func TestICMPFilter(t *testing.T) {
 func TestSetICMPFilter(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
diff --git a/ipv6/multicast_test.go b/ipv6/multicast_test.go
index 0c1ac20a..fc10ce10 100644
--- a/ipv6/multicast_test.go
+++ b/ipv6/multicast_test.go
@@ -31,16 +31,16 @@ func TestPacketConnReadWriteMulticastUDP(t *testing.T) {
 	switch runtime.GOOS {
 	case "freebsd": // due to a bug on loopback marking
 		// See http://www.freebsd.org/cgi/query-pr.cgi?pr=180065.
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
 	}
 	ifi := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagMulticast|net.FlagLoopback)
 	if ifi == nil {
-		t.Skipf("not available on %q", runtime.GOOS)
+		t.Skipf("not available on %s", runtime.GOOS)
 	}
 
 	for _, tt := range packetConnReadWriteMulticastUDPTests {
@@ -64,7 +64,7 @@ func TestPacketConnReadWriteMulticastUDP(t *testing.T) {
 				switch runtime.GOOS {
 				case "freebsd", "linux":
 				default: // platforms that don't support MLDv2 fail here
-					t.Logf("not supported on %q", runtime.GOOS)
+					t.Logf("not supported on %s", runtime.GOOS)
 					continue
 				}
 				t.Fatal(err)
@@ -95,7 +95,7 @@ func TestPacketConnReadWriteMulticastUDP(t *testing.T) {
 		for i, toggle := range []bool{true, false, true} {
 			if err := p.SetControlMessage(cf, toggle); err != nil {
 				if nettest.ProtocolNotSupported(err) {
-					t.Logf("not supported on %q", runtime.GOOS)
+					t.Logf("not supported on %s", runtime.GOOS)
 					continue
 				}
 				t.Fatal(err)
@@ -133,9 +133,9 @@ func TestPacketConnReadWriteMulticastICMP(t *testing.T) {
 	switch runtime.GOOS {
 	case "freebsd": // due to a bug on loopback marking
 		// See http://www.freebsd.org/cgi/query-pr.cgi?pr=180065.
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -145,7 +145,7 @@ func TestPacketConnReadWriteMulticastICMP(t *testing.T) {
 	}
 	ifi := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagMulticast|net.FlagLoopback)
 	if ifi == nil {
-		t.Skipf("not available on %q", runtime.GOOS)
+		t.Skipf("not available on %s", runtime.GOOS)
 	}
 
 	for _, tt := range packetConnReadWriteMulticastICMPTests {
@@ -168,7 +168,7 @@ func TestPacketConnReadWriteMulticastICMP(t *testing.T) {
 				switch runtime.GOOS {
 				case "freebsd", "linux":
 				default: // platforms that don't support MLDv2 fail here
-					t.Logf("not supported on %q", runtime.GOOS)
+					t.Logf("not supported on %s", runtime.GOOS)
 					continue
 				}
 				t.Fatal(err)
@@ -228,7 +228,7 @@ func TestPacketConnReadWriteMulticastICMP(t *testing.T) {
 			}
 			if err := p.SetControlMessage(cf, toggle); err != nil {
 				if nettest.ProtocolNotSupported(err) {
-					t.Logf("not supported on %q", runtime.GOOS)
+					t.Logf("not supported on %s", runtime.GOOS)
 					continue
 				}
 				t.Fatal(err)
@@ -246,7 +246,7 @@ func TestPacketConnReadWriteMulticastICMP(t *testing.T) {
 			if n, cm, _, err := p.ReadFrom(rb); err != nil {
 				switch runtime.GOOS {
 				case "darwin": // older darwin kernels have some limitation on receiving icmp packet through raw socket
-					t.Logf("not supported on %q", runtime.GOOS)
+					t.Logf("not supported on %s", runtime.GOOS)
 					continue
 				}
 				t.Fatal(err)
diff --git a/ipv6/multicastlistener_test.go b/ipv6/multicastlistener_test.go
index 41e7235e..9711f751 100644
--- a/ipv6/multicastlistener_test.go
+++ b/ipv6/multicastlistener_test.go
@@ -23,7 +23,7 @@ var udpMultipleGroupListenerTests = []net.Addr{
 func TestUDPSinglePacketConnWithMultipleGroupListeners(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -63,7 +63,7 @@ func TestUDPSinglePacketConnWithMultipleGroupListeners(t *testing.T) {
 func TestUDPMultiplePacketConnWithMultipleGroupListeners(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -115,7 +115,7 @@ func TestUDPMultiplePacketConnWithMultipleGroupListeners(t *testing.T) {
 func TestUDPPerInterfaceSinglePacketConnWithSingleGroupListener(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -158,7 +158,7 @@ func TestUDPPerInterfaceSinglePacketConnWithSingleGroupListener(t *testing.T) {
 func TestIPSinglePacketConnWithSingleGroupListener(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -200,9 +200,9 @@ func TestIPSinglePacketConnWithSingleGroupListener(t *testing.T) {
 func TestIPPerInterfaceSinglePacketConnWithSingleGroupListener(t *testing.T) {
 	switch runtime.GOOS {
 	case "darwin", "dragonfly", "openbsd": // platforms that return fe80::1%lo0: bind: can't assign requested address
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
diff --git a/ipv6/multicastsockopt_test.go b/ipv6/multicastsockopt_test.go
index bf59750c..fe0e6e1b 100644
--- a/ipv6/multicastsockopt_test.go
+++ b/ipv6/multicastsockopt_test.go
@@ -27,14 +27,14 @@ var packetConnMulticastSocketOptionTests = []struct {
 func TestPacketConnMulticastSocketOptions(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
 	}
 	ifi := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagMulticast|net.FlagLoopback)
 	if ifi == nil {
-		t.Skipf("not available on %q", runtime.GOOS)
+		t.Skipf("not available on %s", runtime.GOOS)
 	}
 
 	m, ok := nettest.SupportsRawIPSocket()
@@ -120,7 +120,7 @@ func testSourceSpecificMulticastSocketOptions(t *testing.T, c testIPv6MulticastC
 		switch runtime.GOOS {
 		case "freebsd", "linux":
 		default: // platforms that don't support MLDv2 fail here
-			t.Logf("not supported on %q", runtime.GOOS)
+			t.Logf("not supported on %s", runtime.GOOS)
 			return
 		}
 		t.Error(err)
diff --git a/ipv6/readwrite_test.go b/ipv6/readwrite_test.go
index c5d295cb..ff4ea2b5 100644
--- a/ipv6/readwrite_test.go
+++ b/ipv6/readwrite_test.go
@@ -102,7 +102,7 @@ func benchmarkReadWriteIPv6UDP(b *testing.B, p *ipv6.PacketConn, wb, rb []byte,
 func TestPacketConnConcurrentReadWriteUnicastUDP(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -127,7 +127,7 @@ func TestPacketConnConcurrentReadWriteUnicastUDP(t *testing.T) {
 
 	if err := p.SetControlMessage(cf, true); err != nil { // probe before test
 		if nettest.ProtocolNotSupported(err) {
-			t.Skipf("not supported on %q", runtime.GOOS)
+			t.Skipf("not supported on %s", runtime.GOOS)
 		}
 		t.Fatal(err)
 	}
diff --git a/ipv6/sockopt_test.go b/ipv6/sockopt_test.go
index 7dd95c71..9c219031 100644
--- a/ipv6/sockopt_test.go
+++ b/ipv6/sockopt_test.go
@@ -20,7 +20,7 @@ var supportsIPv6 bool = nettest.SupportsIPv6()
 func TestConnInitiatorPathMTU(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -44,7 +44,7 @@ func TestConnInitiatorPathMTU(t *testing.T) {
 	if pmtu, err := ipv6.NewConn(c).PathMTU(); err != nil {
 		switch runtime.GOOS {
 		case "darwin": // older darwin kernels don't support IPV6_PATHMTU option
-			t.Logf("not supported on %q", runtime.GOOS)
+			t.Logf("not supported on %s", runtime.GOOS)
 		default:
 			t.Fatal(err)
 		}
@@ -58,7 +58,7 @@ func TestConnInitiatorPathMTU(t *testing.T) {
 func TestConnResponderPathMTU(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -82,7 +82,7 @@ func TestConnResponderPathMTU(t *testing.T) {
 	if pmtu, err := ipv6.NewConn(c).PathMTU(); err != nil {
 		switch runtime.GOOS {
 		case "darwin": // older darwin kernels don't support IPV6_PATHMTU option
-			t.Logf("not supported on %q", runtime.GOOS)
+			t.Logf("not supported on %s", runtime.GOOS)
 		default:
 			t.Fatal(err)
 		}
@@ -96,7 +96,7 @@ func TestConnResponderPathMTU(t *testing.T) {
 func TestPacketConnChecksum(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
diff --git a/ipv6/unicast_test.go b/ipv6/unicast_test.go
index 30660cd0..61656983 100644
--- a/ipv6/unicast_test.go
+++ b/ipv6/unicast_test.go
@@ -21,7 +21,7 @@ import (
 func TestPacketConnReadWriteUnicastUDP(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -54,7 +54,7 @@ func TestPacketConnReadWriteUnicastUDP(t *testing.T) {
 	for i, toggle := range []bool{true, false, true} {
 		if err := p.SetControlMessage(cf, toggle); err != nil {
 			if nettest.ProtocolNotSupported(err) {
-				t.Skipf("not supported on %q", runtime.GOOS)
+				t.Skipf("not supported on %s", runtime.GOOS)
 			}
 			t.Fatal(err)
 		}
@@ -84,7 +84,7 @@ func TestPacketConnReadWriteUnicastUDP(t *testing.T) {
 func TestPacketConnReadWriteUnicastICMP(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -149,7 +149,7 @@ func TestPacketConnReadWriteUnicastICMP(t *testing.T) {
 		}
 		if err := p.SetControlMessage(cf, toggle); err != nil {
 			if nettest.ProtocolNotSupported(err) {
-				t.Skipf("not supported on %q", runtime.GOOS)
+				t.Skipf("not supported on %s", runtime.GOOS)
 			}
 			t.Fatal(err)
 		}
@@ -169,7 +169,7 @@ func TestPacketConnReadWriteUnicastICMP(t *testing.T) {
 		if n, cm, _, err := p.ReadFrom(rb); err != nil {
 			switch runtime.GOOS {
 			case "darwin": // older darwin kernels have some limitation on receiving icmp packet through raw socket
-				t.Logf("not supported on %q", runtime.GOOS)
+				t.Logf("not supported on %s", runtime.GOOS)
 				continue
 			}
 			t.Fatal(err)
diff --git a/ipv6/unicastsockopt_test.go b/ipv6/unicastsockopt_test.go
index 51448d45..7bb2e440 100644
--- a/ipv6/unicastsockopt_test.go
+++ b/ipv6/unicastsockopt_test.go
@@ -17,7 +17,7 @@ import (
 func TestConnUnicastSocketOptions(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -53,7 +53,7 @@ var packetConnUnicastSocketOptionTests = []struct {
 func TestPacketConnUnicastSocketOptions(t *testing.T) {
 	switch runtime.GOOS {
 	case "nacl", "plan9", "solaris", "windows":
-		t.Skipf("not supported on %q", runtime.GOOS)
+		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if !supportsIPv6 {
 		t.Skip("ipv6 is not supported")
@@ -87,7 +87,7 @@ func testUnicastSocketOptions(t *testing.T, c testIPv6UnicastConn) {
 	if err := c.SetTrafficClass(tclass); err != nil {
 		switch runtime.GOOS {
 		case "darwin": // older darwin kernels don't support IPV6_TCLASS option
-			t.Logf("not supported on %q", runtime.GOOS)
+			t.Logf("not supported on %s", runtime.GOOS)
 			goto next
 		}
 		t.Fatal(err)