diff --git a/esp-idf.nix b/esp-idf.nix
index 7f3daec..dd3cbfa 100644
--- a/esp-idf.nix
+++ b/esp-idf.nix
@@ -3,15 +3,16 @@
 let
   version = "v4.1-dev";
 
-  pypkgs = python-packages: with python-packages; [
-    pyserial
-    click
-    cryptography
-    future
-    pyparsing
-    pyelftools
-    setuptools
-  ];
+  pypkgs = python-packages:
+    with python-packages; [
+      pyserial
+      click
+      cryptography
+      future
+      pyparsing
+      pyelftools
+      setuptools
+    ];
   python = pkgs.python2.withPackages pypkgs;
 
 in stdenv.mkDerivation rec {
@@ -20,14 +21,12 @@ in stdenv.mkDerivation rec {
   src = fetchFromGitHub {
     owner = "espressif";
     repo = "esp-idf";
-    rev  = "${version}";
+    rev = "${version}";
     fetchSubmodules = true;
     sha256 = "0d1iqxz1jqz3rrk2c5dq33wp1v71d9190wv3bnigxlp5kcsj0j1w";
   };
 
-  buildInputs = [
-    python
-  ];
+  buildInputs = [ python ];
 
   propagatedBuildInputs = [
     pkgs.cmake
@@ -50,7 +49,8 @@ in stdenv.mkDerivation rec {
 
   meta = with stdenv.lib; {
     description = "ESP IDF";
-    homepage = https://docs.espressif.com/projects/esp-idf/en/stable/get-started/linux-setup.html;
+    homepage =
+      "https://docs.espressif.com/projects/esp-idf/en/stable/get-started/linux-setup.html";
     license = licenses.gpl3;
   };
 }
\ No newline at end of file
diff --git a/esp32-toolchain.nix b/esp32-toolchain.nix
index f61549a..754900a 100644
--- a/esp32-toolchain.nix
+++ b/esp32-toolchain.nix
@@ -6,15 +6,15 @@ let
     targetPkgs = pkgs: with pkgs; [ zlib ];
     runScript = "";
   };
-in
 
-stdenv.mkDerivation rec {
+in stdenv.mkDerivation rec {
   name = "esp32-toolchain";
   version = "2019r2";
 
   src = fetchurl {
     # https://github.com/espressif/esp-idf/blob/release/v4.1/tools/tools.json#L27
-    url = "https://dl.espressif.com/dl/xtensa-esp32-elf-gcc8_2_0-esp-2019r2-linux-amd64.tar.gz";
+    url =
+      "https://dl.espressif.com/dl/xtensa-esp32-elf-gcc8_2_0-esp-2019r2-linux-amd64.tar.gz";
     sha256 = "1pzv1r9kzizh5gi3gsbs6jg8rs1yqnmf5rbifbivz34cplfprm76";
   };
 
@@ -35,7 +35,8 @@ stdenv.mkDerivation rec {
 
   meta = with stdenv.lib; {
     description = "ESP32 toolchain";
-    homepage = https://docs.espressif.com/projects/esp-idf/en/stable/get-started/linux-setup.html;
+    homepage =
+      "https://docs.espressif.com/projects/esp-idf/en/stable/get-started/linux-setup.html";
     license = licenses.gpl3;
   };
 }
\ No newline at end of file
diff --git a/shell.nix b/shell.nix
index c56257f..7fc8ca6 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,19 +1,12 @@
-{ pkgs ? import <nixpkgs> {} }:
-let 
-  esp-idf = (pkgs.callPackage ./esp-idf.nix {});
-  esp32-toolchain = (pkgs.callPackage ./esp32-toolchain.nix {});
-in
-  pkgs.mkShell {
-    buildInputs = [ 
-      esp-idf
-      esp32-toolchain
-    ];
-    shellHook = ''
-set -e
-
-export IDF_PATH=${esp-idf}
-
-export NIX_CFLAGS_LINK=-lncurses
-export PATH=$PATH:$IDF_PATH/tools
-    '';
+{ pkgs ? import <nixpkgs> { } }:
+let
+  esp-idf = (pkgs.callPackage ./esp-idf.nix { });
+  esp32-toolchain = (pkgs.callPackage ./esp32-toolchain.nix { });
+in pkgs.mkShell {
+  buildInputs = [ esp-idf esp32-toolchain ];
+  shellHook = ''
+    export IDF_PATH="${esp-idf.outPath}"
+    export NIX_CFLAGS_LINK=-lncurses
+    export PATH=$PATH:$IDF_PATH/tools
+  '';
 }