diff --git a/nix/microvm/base.nix b/nix/microvm/base.nix
index 5ae6b9bd..992e9622 100644
--- a/nix/microvm/base.nix
+++ b/nix/microvm/base.nix
@@ -214,7 +214,7 @@ in {
         "nix-command"
         "flakes"
       ];
-      trusted-users = ["root"];
+      trusted-users = ["root" "spindle-workflow"];
       allowed-users = ["spindle-workflow"];
     };
     registry.nixpkgs.to = {
diff --git a/nix/pkgs/spindle-alpine-image.nix b/nix/pkgs/spindle-alpine-image.nix
index dea9bb75..46701877 100644
--- a/nix/pkgs/spindle-alpine-image.nix
+++ b/nix/pkgs/spindle-alpine-image.nix
@@ -102,7 +102,7 @@
   # mirror nix/microvm/base.nix and nix/modules/shuttle.nix
   nixConf = writeText "nix.conf" ''
     experimental-features = nix-command flakes
-    trusted-users = root
+    trusted-users = root spindle-workflow
     allowed-users = spindle-workflow
     post-build-hook = /usr/libexec/spindle-post-build-hook
     # keep build sandboxes on the /workspace disk, not the RAM-backed root tmpfs