diff --git a/libraries/libldap/dnssrv.c b/libraries/libldap/dnssrv.c
index 0baaf875ad..b9279a1d82 100644
--- a/libraries/libldap/dnssrv.c
+++ b/libraries/libldap/dnssrv.c
@@ -230,6 +230,9 @@ int ldap_domain2hostlist(
 	/* Bind 8/9 interface */
 	p += NS_HFIXEDSZ;
 #else
+#ifndef	HFIXEDSZ
+#define	HFIXEDSZ	sizeof(HEADER)
+#endif
 	/* Bind 4 interface */
 	p += HFIXEDSZ;
 #endif