diff --git a/src/shrpx_worker.cc b/src/shrpx_worker.cc
index 72113cb3..b04d19c8 100644
--- a/src/shrpx_worker.cc
+++ b/src/shrpx_worker.cc
@@ -844,8 +844,8 @@ int Worker::create_quic_server_socket(UpstreamAddr &faddr) {
         continue;
       }
 
-#  if defined(IPV6_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
-      int mtu_disc = IP_PMTUDISC_DO;
+#  if defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
+      int mtu_disc = IPV6_PMTUDISC_DO;
       if (setsockopt(fd, IPPROTO_IPV6, IPV6_MTU_DISCOVER, &mtu_disc,
                      static_cast<socklen_t>(sizeof(mtu_disc))) == -1) {
         auto error = errno;