diff --git a/home-manager/home.nix b/home-manager/home.nix
index 054b91c..240b949 100644
--- a/home-manager/home.nix
+++ b/home-manager/home.nix
@@ -60,8 +60,10 @@
       commit.gpgsign = true;
       gpg.program = "${nixpkgs.gnupg}/bin/gpg";
       user.signingkey =
-        if machinename == "darwin" || machinename == "earthworm"
+        if machinename == "darwin"
         then "7C97D679CF3BC4F9"
+        else if machinename == "earthworm"
+        then "6E8B1BA1148AD7C9"
         else if machinename == "capybara"
         then "AE90453E879DBCFA"
         else throw "unrecognised machine name!";