diff --git a/modules/microvm-host.nix b/modules/microvm-host.nix
index a3e256c3..e3a94524 100644
--- a/modules/microvm-host.nix
+++ b/modules/microvm-host.nix
@@ -60,9 +60,6 @@
     nix.settings = {
       min-free = 128000000;
       max-free = 1000000000;
-      # fetch github-prebuilt microvm-kernels
-      substituters = [ "https://microvm.cachix.org" ];
-      trusted-public-keys = [ "microvm.cachix.org-1:oXnBc6hRE3eX5rSYdRyMYXnfzcCxC7yKPTbZXALsqys=" ];
     };
 
     environment.systemPackages = [ (