diff --git a/machines/enigma/default.nix b/machines/enigma/default.nix
index 6200e77..a542ab4 100644
--- a/machines/enigma/default.nix
+++ b/machines/enigma/default.nix
@@ -155,7 +155,7 @@
 
   services.printing.enable = true;
   services.avahi.enable = true;
-  services.avahi.nssmdns = true;
+  services.avahi.nssmdns4 = true;
   # for a WiFi printer
   services.avahi.openFirewall = true;
 
diff --git a/machines/x2100/default.nix b/machines/x2100/default.nix
index 36946fe..f75884d 100644
--- a/machines/x2100/default.nix
+++ b/machines/x2100/default.nix
@@ -120,7 +120,7 @@
 
   services.printing.enable = true;
   services.avahi.enable = true;
-  services.avahi.nssmdns = true;
+  services.avahi.nssmdns4 = true;
   # for a WiFi printer
   services.avahi.openFirewall = true;