diff --git a/lyrathorpe/home/git.nix b/lyrathorpe/home/git.nix
index 7300559..9300ecf 100644
--- a/lyrathorpe/home/git.nix
+++ b/lyrathorpe/home/git.nix
@@ -77,12 +77,14 @@ in
         cc = "!cz commit";
       };
 
-      # SSH commit signing on personal hosts too (the work module sets the same
-      # on the work host). mkDefault so a host without the key in its ssh-agent
-      # can override to false -- otherwise commits there would fail. Reuses the
-      # existing ssh key; a dedicated personal key can be swapped in later.
+      # SSH commit signing. This personal key is the default; the work module
+      # (work.nix) overrides it with the work key on the EDaaS host, the same way
+      # user.email is overridden -- so mkDefault here lets that plain definition
+      # win instead of conflicting. gpgsign is mkDefault too, so a host without
+      # the key in its ssh-agent can override it to false rather than fail every
+      # commit.
       gpg.format = "ssh";
-      user.signingkey = "key::ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPDxHvdMTOzpFWUFMtCP7C/4tIOUO3GIO2QPvaifSnWH lyrathorpe@Lyra-MBA";
+      user.signingkey = lib.mkDefault "key::ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPDxHvdMTOzpFWUFMtCP7C/4tIOUO3GIO2QPvaifSnWH lyrathorpe@Lyra-MBA";
       commit.gpgsign = lib.mkDefault true;
       tag.gpgsign = lib.mkDefault true;
     };