diff --git a/ipv4/multicast_test.go b/ipv4/multicast_test.go
index 2136a3c..fd9efe0 100644
--- a/ipv4/multicast_test.go
+++ b/ipv4/multicast_test.go
@@ -29,7 +29,7 @@
 
 func TestPacketConnReadWriteMulticastUDP(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "solaris", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "solaris", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagMulticast|net.FlagLoopback)
@@ -117,7 +117,7 @@
 
 func TestPacketConnReadWriteMulticastICMP(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "solaris", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "solaris", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if m, ok := nettest.SupportsRawIPSocket(); !ok {
@@ -227,6 +227,10 @@
 }
 
 func TestRawConnReadWriteMulticastICMP(t *testing.T) {
+	switch runtime.GOOS {
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "solaris", "windows":
+		t.Skipf("not supported on %s", runtime.GOOS)
+	}
 	if testing.Short() {
 		t.Skip("to avoid external network")
 	}
diff --git a/ipv4/multicastlistener_test.go b/ipv4/multicastlistener_test.go
index ba2480e..73e509d 100644
--- a/ipv4/multicastlistener_test.go
+++ b/ipv4/multicastlistener_test.go
@@ -21,7 +21,7 @@
 
 func TestUDPSinglePacketConnWithMultipleGroupListeners(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if testing.Short() {
@@ -61,7 +61,7 @@
 
 func TestUDPMultiplePacketConnWithMultipleGroupListeners(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if testing.Short() {
@@ -116,7 +116,7 @@
 
 func TestUDPPerInterfaceSinglePacketConnWithSingleGroupListener(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if testing.Short() {
@@ -172,7 +172,7 @@
 
 func TestIPSingleRawConnWithSingleGroupListener(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if testing.Short() {
@@ -217,7 +217,7 @@
 
 func TestIPPerInterfaceSingleRawConnWithSingleGroupListener(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if testing.Short() {
diff --git a/ipv4/multicastsockopt_test.go b/ipv4/multicastsockopt_test.go
index c0a2680..fd783d0 100644
--- a/ipv4/multicastsockopt_test.go
+++ b/ipv4/multicastsockopt_test.go
@@ -26,7 +26,7 @@
 
 func TestPacketConnMulticastSocketOptions(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagMulticast|net.FlagLoopback)
@@ -66,7 +66,7 @@
 
 func TestRawConnMulticastSocketOptions(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if m, ok := nettest.SupportsRawIPSocket(); !ok {
@@ -111,6 +111,8 @@
 }
 
 func testMulticastSocketOptions(t *testing.T, c testIPv4MulticastConn, ifi *net.Interface, grp net.Addr) {
+	t.Helper()
+
 	const ttl = 255
 	if err := c.SetMulticastTTL(ttl); err != nil {
 		t.Error(err)
@@ -149,6 +151,8 @@
 }
 
 func testSourceSpecificMulticastSocketOptions(t *testing.T, c testIPv4MulticastConn, ifi *net.Interface, grp, src net.Addr) {
+	t.Helper()
+
 	// MCAST_JOIN_GROUP -> MCAST_BLOCK_SOURCE -> MCAST_UNBLOCK_SOURCE -> MCAST_LEAVE_GROUP
 	if err := c.JoinGroup(ifi, grp); err != nil {
 		t.Error(err)
diff --git a/ipv4/readwrite_test.go b/ipv4/readwrite_test.go
index d6e35be..acf87d1 100644
--- a/ipv4/readwrite_test.go
+++ b/ipv4/readwrite_test.go
@@ -19,6 +19,11 @@
 )
 
 func BenchmarkReadWriteUnicast(b *testing.B) {
+	switch runtime.GOOS {
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
+		b.Skipf("not supported on %s", runtime.GOOS)
+	}
+
 	c, err := nettest.NewLocalPacketListener("udp4")
 	if err != nil {
 		b.Skipf("not supported on %s/%s: %v", runtime.GOOS, runtime.GOARCH, err)
@@ -63,7 +68,7 @@
 
 func BenchmarkPacketConnReadWriteUnicast(b *testing.B) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		b.Skipf("not supported on %s", runtime.GOOS)
 	}
 
@@ -213,7 +218,7 @@
 
 func TestPacketConnConcurrentReadWriteUnicastUDP(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 
@@ -293,7 +298,7 @@
 
 func TestPacketConnConcurrentReadWriteUnicast(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 
@@ -351,6 +356,8 @@
 }
 
 func testPacketConnConcurrentReadWriteUnicast(t *testing.T, p *ipv4.PacketConn, data []byte, dst net.Addr, batch bool) {
+	t.Helper()
+
 	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback)
 	cf := ipv4.FlagTTL | ipv4.FlagSrc | ipv4.FlagDst | ipv4.FlagInterface
 
diff --git a/ipv4/unicast_test.go b/ipv4/unicast_test.go
index 274a558..a75f54e 100644
--- a/ipv4/unicast_test.go
+++ b/ipv4/unicast_test.go
@@ -20,7 +20,7 @@
 
 func TestPacketConnReadWriteUnicastUDP(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback)
@@ -71,7 +71,7 @@
 
 func TestPacketConnReadWriteUnicastICMP(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if m, ok := nettest.SupportsRawIPSocket(); !ok {
@@ -157,7 +157,7 @@
 
 func TestRawConnReadWriteUnicastICMP(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if m, ok := nettest.SupportsRawIPSocket(); !ok {
diff --git a/ipv4/unicastsockopt_test.go b/ipv4/unicastsockopt_test.go
index 2bfda7f..9a279b7 100644
--- a/ipv4/unicastsockopt_test.go
+++ b/ipv4/unicastsockopt_test.go
@@ -16,7 +16,7 @@
 
 func TestConnUnicastSocketOptions(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback)
@@ -62,7 +62,7 @@
 
 func TestPacketConnUnicastSocketOptions(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback)
@@ -88,7 +88,7 @@
 
 func TestRawConnUnicastSocketOptions(t *testing.T) {
 	switch runtime.GOOS {
-	case "js", "nacl", "plan9", "windows":
+	case "aix", "fuchsia", "hurd", "js", "nacl", "plan9", "windows":
 		t.Skipf("not supported on %s", runtime.GOOS)
 	}
 	if m, ok := nettest.SupportsRawIPSocket(); !ok {
@@ -121,6 +121,8 @@
 }
 
 func testUnicastSocketOptions(t *testing.T, c testIPv4UnicastConn) {
+	t.Helper()
+
 	tos := iana.DiffServCS0 | iana.NotECNTransport
 	switch runtime.GOOS {
 	case "windows":