diff --git a/mail/sendmail/sendmail.conf b/mail/sendmail/sendmail.conf
index b88603814..d95f8a9ca 100644
--- a/mail/sendmail/sendmail.conf
+++ b/mail/sendmail/sendmail.conf
@@ -55,6 +55,14 @@ sm_main() {
 		sm_appenddef "confINCDIR" "-L$( pkgprefix -r includedir openssl )"
 	fi
 
+	# LDAP support
+	if pkginstalled -f openldap; then
+		sm_appenddef "confENVDEF" "-DLDAPMAP"
+		sm_appenddef "confLIBS" "-lldap -llber"
+		sm_appenddef "confLIBDIR" "-L$( pkgprefix -r libdir openldap )"
+		sm_appenddef "confINCDIR" "-L$( pkgprefix -r includedir openldap )"
+	fi
+
 	cd ..; ./Build; ./Build install
 	install_setmailer sendmail
 }