diff --git a/slirp/ip6_icmp.c b/slirp/ip6_icmp.c
index d0f5cc1456..777eb574be 100644
--- a/slirp/ip6_icmp.c
+++ b/slirp/ip6_icmp.c
@@ -144,6 +144,9 @@ void ndp_send_ra(Slirp *slirp)
     struct mbuf *t = m_get(slirp);
     struct ip6 *rip = mtod(t, struct ip6 *);
     size_t pl_size = 0;
+    struct in6_addr addr;
+    uint32_t scope_id;
+
     rip->ip_src = (struct in6_addr)LINKLOCAL_ADDR;
     rip->ip_dst = (struct in6_addr)ALLNODES_MULTICAST;
     rip->ip_nh = IPPROTO_ICMPV6;
@@ -189,18 +192,18 @@ void ndp_send_ra(Slirp *slirp)
     t->m_data += NDPOPT_PREFIXINFO_LEN;
     pl_size += NDPOPT_PREFIXINFO_LEN;
 
-#ifndef _WIN32
     /* Prefix information (NDP option) */
-    /* disabled for windows for now, until get_dns6_addr is implemented */
-    struct ndpopt *opt3 = mtod(t, struct ndpopt *);
-    opt3->ndpopt_type = NDPOPT_RDNSS;
-    opt3->ndpopt_len = NDPOPT_RDNSS_LEN / 8;
-    opt3->ndpopt_rdnss.reserved = 0;
-    opt3->ndpopt_rdnss.lifetime = htonl(2 * NDP_MaxRtrAdvInterval);
-    opt3->ndpopt_rdnss.addr = slirp->vnameserver_addr6;
-    t->m_data += NDPOPT_RDNSS_LEN;
-    pl_size += NDPOPT_RDNSS_LEN;
-#endif
+    if (get_dns6_addr(&addr, &scope_id) >= 0) {
+        /* Host system does have an IPv6 DNS server, announce our proxy.  */
+        struct ndpopt *opt3 = mtod(t, struct ndpopt *);
+        opt3->ndpopt_type = NDPOPT_RDNSS;
+        opt3->ndpopt_len = NDPOPT_RDNSS_LEN / 8;
+        opt3->ndpopt_rdnss.reserved = 0;
+        opt3->ndpopt_rdnss.lifetime = htonl(2 * NDP_MaxRtrAdvInterval);
+        opt3->ndpopt_rdnss.addr = slirp->vnameserver_addr6;
+        t->m_data += NDPOPT_RDNSS_LEN;
+        pl_size += NDPOPT_RDNSS_LEN;
+    }
 
     rip->ip_pl = htons(pl_size);
     t->m_data -= sizeof(struct ip6) + pl_size;