diff --git a/overlay.nix b/overlay.nix
index f92fb76..4929ed6 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -1,11 +1,13 @@
 final: prev:
-let extraPkgs = import ./pkgs/default.nix { inherit (final) callPackage; };
+let
+  extraPkgs = import ./pkgs/default.nix { inherit (final) callPackage; };
+  inherit (final) fetchpatch;
 in
 extraPkgs // {
   strace = prev.strace.override { libunwind = null; };
 
   s6 = prev.s6.overrideAttrs(o:
-    let patch = final.fetchpatch {
+    let patch = fetchpatch {
           # add "p" directive in s6-log
           url = "https://github.com/skarnet/s6/commit/ddc76841398dfd5e18b22943727ad74b880236d3.patch";
           hash = "sha256-fBtUinBdp5GqoxgF6fcR44Tu8hakxs/rOShhuZOgokc=";