--- a/smtpd/to.c
+++ b/smtpd/to.c
@@ -210,7 +210,7 @@
 #if HAVE_STRUCT_TM_TM_GMTOFF
 	offset = lt->tm_gmtoff;
 	tz = lt->tm_zone;
-#elif defined HAVE_DECL_ALTZONE && defined HAVE_DECL_TIMEZONE
+#elif HAVE_DECL_ALTZONE && HAVE_DECL_TIMEZONE
 	offset = lt->tm_isdst > 0 ? altzone : timezone;
 	tz = lt->tm_isdst > 0 ? tzname[1] : tzname[0];
 #endif