diff --git a/modules/services/docker-mailserver/default.nix b/modules/services/docker-mailserver/default.nix
index 6a7b592..13e0dc3 100644
--- a/modules/services/docker-mailserver/default.nix
+++ b/modules/services/docker-mailserver/default.nix
@@ -64,7 +64,9 @@ in
       fsType = "nfs";
       options = [
         "hard"
+        "nfsvers=4.0"
         "noatime"
+        "nolock"
         "rw"
       ];
     };