diff --git a/modules/hosts/darwin/default.nix b/modules/hosts/darwin/default.nix
index a6b67be..1e87067 100644
--- a/modules/hosts/darwin/default.nix
+++ b/modules/hosts/darwin/default.nix
@@ -106,11 +106,13 @@
       substituters = [
         "https://cache.nixos.org" # default one
         "https://cache.flox.dev"
+        "https://cache.thalheim.io"
         "https://nixpkgs-terraform.cachix.org"
       ];
       trusted-public-keys = [
         "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=" # default one
         "flox-cache-public-1:7F4OyH7ZCnFhcze3fJdfyXYLQw/aV7GEed86nQ7IsOs="
+        "cache.thalheim.io-1:R7msbosLEZKrxk/lKxf9BTjOOH7Ax3H0Qj0/6wiHOgc="
         "nixpkgs-terraform.cachix.org-1:8Sit092rIdAVENA3ZVeH9hzSiqI/jng6JiCrQ1Dmusw="
       ];
       trusted-users = [ "@admin" "${username}" ];
diff --git a/modules/hosts/nixos/default.nix b/modules/hosts/nixos/default.nix
index 81591c9..f7a0465 100644
--- a/modules/hosts/nixos/default.nix
+++ b/modules/hosts/nixos/default.nix
@@ -51,11 +51,13 @@
     substituters = [
       "https://cache.nixos.org" # default one
       "https://cache.flox.dev"
+      "https://cache.thalheim.io"
       "https://cosmic.cachix.org/"
       "https://nixpkgs-terraform.cachix.org"
     ];
     trusted-public-keys = [
       "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=" # default one
+      "cache.thalheim.io-1:R7msbosLEZKrxk/lKxf9BTjOOH7Ax3H0Qj0/6wiHOgc="
       "cosmic.cachix.org-1:Dya9IyXD4xdBehWjrkPv6rtxpmMdRel02smYzA85dPE="
       "flox-cache-public-1:7F4OyH7ZCnFhcze3fJdfyXYLQw/aV7GEed86nQ7IsOs="
       "nixpkgs-terraform.cachix.org-1:8Sit092rIdAVENA3ZVeH9hzSiqI/jng6JiCrQ1Dmusw="