diff --git a/postfix/src/dns/dns_str_resflags.c b/postfix/src/dns/dns_str_resflags.c
index 5f2cce5e0..472394c3a 100644
--- a/postfix/src/dns/dns_str_resflags.c
+++ b/postfix/src/dns/dns_str_resflags.c
@@ -52,18 +52,28 @@
 static const LONG_NAME_MASK resflag_table[] = {
     "RES_INIT", RES_INIT,
     "RES_DEBUG", RES_DEBUG,
+#ifdef RES_AAONLY
     "RES_AAONLY", RES_AAONLY,
+#endif
     "RES_USEVC", RES_USEVC,
+#ifdef RES_PRIMARY
     "RES_PRIMARY", RES_PRIMARY,
+#endif
     "RES_IGNTC", RES_IGNTC,
     "RES_RECURSE", RES_RECURSE,
     "RES_DEFNAMES", RES_DEFNAMES,
     "RES_STAYOPEN", RES_STAYOPEN,
     "RES_DNSRCH", RES_DNSRCH,
+#ifdef RES_INSECURE1
     "RES_INSECURE1", RES_INSECURE1,
+#endif
+#ifdef RES_INSECURE2
     "RES_INSECURE2", RES_INSECURE2,
+#endif
     "RES_NOALIASES", RES_NOALIASES,
+#ifdef RES_USE_INET6
     "RES_USE_INET6", RES_USE_INET6,
+#endif
 #ifdef RES_ROTATE
     "RES_ROTATE", RES_ROTATE,
 #endif