diff --git a/ipv6/errors_other_test.go b/ipv6/errors_other_test.go
new file mode 100644
index 0000000..5a87d73
--- /dev/null
+++ b/ipv6/errors_other_test.go
@@ -0,0 +1,14 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !(aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris)
+// +build !aix,!darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd,!solaris
+
+package ipv6_test
+
+// isENOBUFS reports whether err is unix.ENOBUFS.
+// (Always false on non-Unix platforms.)
+func isENOBUFS(err error) bool {
+	return false
+}
diff --git a/ipv6/errors_unix_test.go b/ipv6/errors_unix_test.go
new file mode 100644
index 0000000..978ae61
--- /dev/null
+++ b/ipv6/errors_unix_test.go
@@ -0,0 +1,20 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package ipv6_test
+
+import (
+	"errors"
+
+	"golang.org/x/sys/unix"
+)
+
+// isENOBUFS reports whether err is unix.ENOBUFS.
+// (Always false on non-Unix platforms.)
+func isENOBUFS(err error) bool {
+	return errors.Is(err, unix.ENOBUFS)
+}
diff --git a/ipv6/multicast_test.go b/ipv6/multicast_test.go
index 7f56927..267098a 100644
--- a/ipv6/multicast_test.go
+++ b/ipv6/multicast_test.go
@@ -10,6 +10,7 @@
 	"os"
 	"runtime"
 	"testing"
+	"time"
 
 	"golang.org/x/net/icmp"
 	"golang.org/x/net/internal/iana"
@@ -100,11 +101,24 @@
 				t.Fatal(err)
 			}
 			cm.HopLimit = i + 1
-			if n, err := p.WriteTo(wb, &cm, &grp); err != nil {
-				t.Fatal(err)
-			} else if n != len(wb) {
-				t.Fatal(err)
+
+			backoff := time.Millisecond
+			for {
+				n, err := p.WriteTo(wb, &cm, &grp)
+				if err != nil {
+					if n == 0 && isENOBUFS(err) {
+						time.Sleep(backoff)
+						backoff *= 2
+						continue
+					}
+					t.Fatal(err)
+				}
+				if n != len(wb) {
+					t.Fatalf("wrote %v bytes; want %v", n, len(wb))
+				}
+				break
 			}
+
 			rb := make([]byte, 128)
 			if n, _, _, err := p.ReadFrom(rb); err != nil {
 				t.Fatal(err)