diff --git a/src/storage/zone.cr b/src/storage/zone.cr
index e7618ed..e90a40b 100644
--- a/src/storage/zone.cr
+++ b/src/storage/zone.cr
@@ -584,8 +584,8 @@ class DNSManager::Storage::Zone
 			end
 
 			# MX target can either be a subdomain or a FQDN.
-			unless (Zone.is_subdomain_valid? @target || Zone.is_domain_valid? @target)
-				errors << "MX invalid target (domain or subdomain): #{@target}"
+			unless Zone.is_domain_valid? @target
+				errors << "MX invalid target (domain): #{@target}"
 			end
 
 			errors