diff --git a/secure/udp_mail.c b/secure/udp_mail.c
index 3203fb9..4bd8d74 100644
--- a/secure/udp_mail.c
+++ b/secure/udp_mail.c
@@ -200,7 +200,7 @@
 {
   string *match;
 
-  match=filter(m_indices((mapping)INETD->query("hosts")),
+  match=filter(m_indices(({mapping})INETD->query("hosts")),
 		#'match_mud_name,lower_case(hostname));
 
   return (sizeof(match)==1);