diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index 06aece31dc4..c1775ea45bd 100644
--- a/src/backend/libpq/pqcomm.c
+++ b/src/backend/libpq/pqcomm.c
@@ -383,7 +383,7 @@ StreamServerPort(int family, char *hostName, unsigned short portNumber,
 		}
 #endif
 
-#ifdef IPV6_V6ONLY
+#if defined(IPV6_V6ONLY) && defined(IPPROTO_IPV6)
 		if (addr->ai_family == AF_INET6)
 		{
 			if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,