diff --git a/default.nix b/default.nix
index 50c85bc..f6a8f72 100644
--- a/default.nix
+++ b/default.nix
@@ -1,5 +1,4 @@
-{ nixpkgs ? <nixpkgs> }:
-import nixpkgs {
+import <nixpkgs> {
   # docker images run on Linux
   system = "x86_64-linux";
   config = {};
diff --git a/release.nix b/release.nix
index bacbcd3..f1e77d7 100644
--- a/release.nix
+++ b/release.nix
@@ -1,4 +1,4 @@
 let
-  pkgs = import ./. {};
+  pkgs = import ./.;
 in
 pkgs.docker-nixpkgs
diff --git a/shell.nix b/shell.nix
index 73b2e2c..dd22871 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,5 +1,4 @@
-{ nixpkgs ? <nixpkgs> }@args:
-with import ./. args;
+with import ./.;
 mkShell {
   buildInputs = [
     jq