diff --git a/modules/services/logging/syslogd.nix b/modules/services/logging/syslogd.nix
index f6eb914b66e7..b600d353fe5d 100644
--- a/modules/services/logging/syslogd.nix
+++ b/modules/services/logging/syslogd.nix
@@ -36,7 +36,7 @@ in
     services.syslogd = {
 
       tty = mkOption {
-        type = types.string;
+        type = types.uniq types.string;
         default = "tty10";
         description = ''
           The tty device on which syslogd will print important log