diff --git a/ops/nixos/swann/default.nix b/ops/nixos/swann/default.nix
index a8863ba919..ba0fab6b60 100644
--- a/ops/nixos/swann/default.nix
+++ b/ops/nixos/swann/default.nix
@@ -815,7 +815,7 @@ in {
     system.stateVersion = "21.03";
   } {
     # Minimize writes to storage.
-    boot.tmpOnTmpfs = true;
+    boot.tmp.useTmpfs = true;
     services.journald.extraConfig = ''
       Storage=volatile
     '';