diff --git a/ops/nixos/lib/common.nix b/ops/nixos/lib/common.nix
index dc02fa6923..dbcf21d708 100644
--- a/ops/nixos/lib/common.nix
+++ b/ops/nixos/lib/common.nix
@@ -57,7 +57,7 @@ in
     environment.systemPackages = with pkgs; [
       vim rxvt_unicode.terminfo tmux rebuilder tailscale rsync libarchive tcpdump restic
       (mercurial.overridePythonAttrs (origAttrs: {
-        propagatedBuildInputs = origAttrs.propagatedBuildInputs ++ [python3Packages.hg-evolve depot.nix.pkgs.hg-git];
+        propagatedBuildInputs = [python3Packages.hg-evolve depot.nix.pkgs.hg-git];
       }))
     ];
 
diff --git a/ops/nixos/lib/home-manager/common.nix b/ops/nixos/lib/home-manager/common.nix
index aea63493c6..20a477b233 100644
--- a/ops/nixos/lib/home-manager/common.nix
+++ b/ops/nixos/lib/home-manager/common.nix
@@ -80,7 +80,7 @@ in
     '')
     rxvt_unicode.terminfo tmux rsync libarchive tcpdump restic
     (mercurial.overridePythonAttrs (origAttrs: {
-      propagatedBuildInputs = origAttrs.propagatedBuildInputs ++ [python3Packages.hg-evolve depot.nix.pkgs.hg-git];
+      propagatedBuildInputs = [python3Packages.hg-evolve depot.nix.pkgs.hg-git];
     }))
   ]));