diff --git a/src/tuntap/icmpv6.go b/src/tuntap/icmpv6.go
index ea1a785..fe80dfb 100644
--- a/src/tuntap/icmpv6.go
+++ b/src/tuntap/icmpv6.go
@@ -313,6 +313,14 @@ func (i *ICMPv6) Solicit(addr address.Address) {
 	}
 }
 
+func (i *ICMPv6) getNeighbor(addr address.Address) (neighbor, bool) {
+	i.peermacsmutex.RLock()
+	defer i.peermacsmutex.RUnlock()
+
+	n, ok := i.peermacs[addr]
+	return n, ok
+}
+
 func (i *ICMPv6) createNDPL2(dst address.Address) ([]byte, error) {
 	// Create the ND payload
 	var payload [28]byte
diff --git a/src/tuntap/iface.go b/src/tuntap/iface.go
index be3988a..9ffde85 100644
--- a/src/tuntap/iface.go
+++ b/src/tuntap/iface.go
@@ -41,7 +41,7 @@ func (tun *TunAdapter) writer() error {
 				return errors.New("Invalid address family")
 			}
 			sendndp := func(dstAddr address.Address) {
-				neigh, known := tun.icmpv6.peermacs[dstAddr]
+				neigh, known := tun.icmpv6.getNeighbor(dstAddr)
 				known = known && (time.Since(neigh.lastsolicitation).Seconds() < 30)
 				if !known {
 					tun.icmpv6.Solicit(dstAddr)
@@ -56,12 +56,12 @@ func (tun *TunAdapter) writer() error {
 					dstAddr = tun.addr
 				}
 			}
-			if neighbor, ok := tun.icmpv6.peermacs[dstAddr]; ok && neighbor.learned {
+			if neighbor, ok := tun.icmpv6.getNeighbor(dstAddr); ok && neighbor.learned {
 				// If we've learned the MAC of a 300::/7 address, for example, or a CKR
 				// address, use the MAC address of that
 				peermac = neighbor.mac
 				peerknown = true
-			} else if neighbor, ok := tun.icmpv6.peermacs[tun.addr]; ok && neighbor.learned {
+			} else if neighbor, ok := tun.icmpv6.getNeighbor(tun.addr); ok && neighbor.learned {
 				// Otherwise send directly to the MAC address of the host if that's
 				// known instead
 				peermac = neighbor.mac