diff --git a/build-project.nix b/build-project.nix
index b4afb22..5fdcc81 100644
--- a/build-project.nix
+++ b/build-project.nix
@@ -5,8 +5,8 @@ let
     pkgs.fetchFromGitHub {
       owner = "justinwoo";
       repo = "easy-purescript-nix";
-      rev = "cc7196bff3fdb5957aabfe22c3fa88267047fe88";
-      sha256 = "1xfl7rnmmcm8qdlsfn3xjv91my6lirs5ysy01bmyblsl10y2z9iw";
+      rev = "e00a54ca6bd0290e8301eff140d109c1f300e40d";
+      sha256 = "1yrnnpxkzs59ik5dj9v67ysn4viff775v24kizpl0ylf24c74928";
     }
   ) {
     inherit pkgs;
@@ -20,5 +20,5 @@ in
 spago2nix.mkBuildProjectOutput {
   src = ./src;
 
-  purs = easy-ps.purs;
+  purs = easy-ps.purs-0_13_8;
 }
diff --git a/ci.nix b/ci.nix
index 510668c..a0d5bc9 100644
--- a/ci.nix
+++ b/ci.nix
@@ -1,14 +1,14 @@
-{ pkgs ? import <nixpkgs> {} }:
-
+{ pkgs ? import <nixpkgs> { } }:
 let
-  easy-ps = import (
-    pkgs.fetchFromGitHub {
-      owner = "justinwoo";
-      repo = "easy-purescript-nix";
-      rev = "cc7196bff3fdb5957aabfe22c3fa88267047fe88";
-      sha256 = "1xfl7rnmmcm8qdlsfn3xjv91my6lirs5ysy01bmyblsl10y2z9iw";
-    }
-  ) {
+  easy-ps = import
+    (
+      pkgs.fetchFromGitHub {
+        owner = "justinwoo";
+        repo = "easy-purescript-nix";
+        rev = "e00a54ca6bd0290e8301eff140d109c1f300e40d";
+        sha256 = "1yrnnpxkzs59ik5dj9v67ysn4viff775v24kizpl0ylf24c74928";
+      }
+    ) {
     inherit pkgs;
   };
 
@@ -18,5 +18,8 @@ let
 
 in
 pkgs.mkShell {
-  buildInputs = [ easy-ps.purs spago2nix ];
+  buildInputs = [
+    easy-ps.purs-0_13_8
+    spago2nix
+  ];
 }
diff --git a/default.nix b/default.nix
index d3f281a..42165d2 100644
--- a/default.nix
+++ b/default.nix
@@ -11,46 +11,46 @@ let
   };
 
 in
-{ pkgs ? import <nixpkgs> {}
+{ pkgs ? import <nixpkgs> { }
 , dhall-json ? (easy-dhall-nix pkgs).dhall-json-simple
 , nodejs ? pkgs.nodejs-10_x
 }:
-
-  let
-    easy-purescript-nix = import (
+let
+  easy-purescript-nix = import
+    (
       pkgs.fetchFromGitHub {
         owner = "justinwoo";
         repo = "easy-purescript-nix";
-        rev = "1ec689df0adf8e8ada7fcfcb513876307ea34226";
-        sha256 = "12hk2zbjkrq2i5fs6xb3x254lnhm9fzkcxph0a7ngxyzfykvf4hi";
+        rev = "e00a54ca6bd0290e8301eff140d109c1f300e40d";
+        sha256 = "1yrnnpxkzs59ik5dj9v67ysn4viff775v24kizpl0ylf24c74928";
       }
     ) {
-      inherit pkgs;
-    };
+    inherit pkgs;
+  };
 
-  in
-    pkgs.stdenv.mkDerivation {
-      name = "spago2nix";
+in
+pkgs.stdenv.mkDerivation {
+  name = "spago2nix";
 
-      src = pkgs.nix-gitignore.gitignoreSource [ ".git" ] ./.;
+  src = pkgs.nix-gitignore.gitignoreSource [ ".git" ] ./.;
 
-      buildInputs = [ pkgs.makeWrapper ];
+  buildInputs = [ pkgs.makeWrapper ];
 
-      installPhase = ''
-        mkdir -p $out/bin
-        target=$out/bin/spago2nix
+  installPhase = ''
+      mkdir -p $out/bin
+      target=$out/bin/spago2nix
 
-        >>$target echo '#!${nodejs}/bin/node'
-        >>$target echo "require('$src/bin/output.js')";
+      >>$target echo '#!${nodejs}/bin/node'
+      >>$target echo "require('$src/bin/output.js')";
 
-        chmod +x $target
+      chmod +x $target
 
-        wrapProgram $target \
-          --prefix PATH : ${pkgs.lib.makeBinPath [
-        pkgs.coreutils
-        pkgs.nix-prefetch-git
-        easy-purescript-nix.spago
-        dhall-json
-      ]}
-      '';
-    }
+      wrapProgram $target \
+        --prefix PATH : ${pkgs.lib.makeBinPath [
+      pkgs.coreutils
+      pkgs.nix-prefetch-git
+      easy-purescript-nix.spago
+      dhall-json
+    ]}
+  '';
+}
diff --git a/mkbin.nix b/mkbin.nix
index decb3db..68ddc4e 100644
--- a/mkbin.nix
+++ b/mkbin.nix
@@ -4,32 +4,32 @@
 #     nix-shell mkbin.nix
 #
 
-{ pkgs ? import <nixpkgs> {}
+{ pkgs ? import <nixpkgs> { }
 , nodejs ? pkgs.nodejs-10_x
 }:
-
-  let
-    easy-purescript-nix = import (
+let
+  easy-purescript-nix = import
+    (
       pkgs.fetchFromGitHub {
         owner = "justinwoo";
         repo = "easy-purescript-nix";
-        rev = "1ec689df0adf8e8ada7fcfcb513876307ea34226";
-        sha256 = "12hk2zbjkrq2i5fs6xb3x254lnhm9fzkcxph0a7ngxyzfykvf4hi";
+        rev = "e00a54ca6bd0290e8301eff140d109c1f300e40d";
+        sha256 = "1yrnnpxkzs59ik5dj9v67ysn4viff775v24kizpl0ylf24c74928";
       }
     ) {
-      inherit pkgs;
-    };
+    inherit pkgs;
+  };
 
-  in
-    pkgs.mkShell {
-      nativeBuildInputs = [
-        easy-purescript-nix.purs
-        easy-purescript-nix.spago
-        nodejs
-      ];
-      shellHook = ''
-        npm install
-        npm run mkbin
-        exit 0
-      '';
-    }
+in
+pkgs.mkShell {
+  nativeBuildInputs = [
+    easy-purescript-nix.purs-0_13_8
+    easy-purescript-nix.spago
+    nodejs
+  ];
+  shellHook = ''
+    npm install
+    npm run mkbin
+    exit 0
+  '';
+}