diff --git a/src/racket/sconfig.h b/src/racket/sconfig.h
index e90093295d..f0bba06980 100644
--- a/src/racket/sconfig.h
+++ b/src/racket/sconfig.h
@@ -756,6 +756,8 @@
 
 # define SIGSET_IS_SIGNAL
 
+# define MZ_TCP_LISTEN_IPV6_ONLY_SOCKOPT
+
 # define USE_TM_GMTOFF_FIELD
 # define USE_TM_ZONE_FIELD