diff --git a/default.nix b/default.nix
index 21c4c4e..c6d3abb 100644
--- a/default.nix
+++ b/default.nix
@@ -173,7 +173,7 @@ let
 
       src = elmCleanSource src;
 
-      buildInputs = with elmPackages; [ elm elm-format nodeSource ];
+      buildInputs = with workingElmPackages; [ elm elm-format nodeSource ];
 
       patchPhase = ''
         ln -sf ${nodeSource}/node_modules .
@@ -193,7 +193,7 @@ let
         export NODE_PATH=$PWD/node_modules
       '';
 
-      buildPhase = elmPackages.fetchElmDeps {
+      buildPhase = workingElmPackages.fetchElmDeps {
         elmPackages = import (src + "/elm-srcs.nix");
         registryDat = src + "/registry.dat";
         elmVersion = "0.19.1";