diff --git a/shell.nix b/shell.nix
index 1274430f9..3c37a979e 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,11 +1,11 @@
-{ nixpkgs ? import <nixpkgs> {}, compiler ? "ghc822" }:
+{ nixpkgs ? import <nixpkgs> {}, compiler ? null }:
 
 let
   inherit (nixpkgs) pkgs;
 
   haskellPackages = if isNull compiler
                        then pkgs.haskellPackages
-                       else pkgs.haskell.packages.${compiler};
+                       else pkgs.haskell.packages."${compiler}";
 
   drv = haskellPackages.callPackage ./uniworx.nix {};
 
diff --git a/stack.nix b/stack.nix
index 720dc860f..93d072683 100644
--- a/stack.nix
+++ b/stack.nix
@@ -2,12 +2,13 @@
 
 let
   inherit (nixpkgs) haskell pkgs;
+  haskellPackages = if ghc.version == pkgs.haskellPackages.ghc.version then pkgs.haskellPackages else pkgs.haskell.packages."ghc${builtins.replaceStrings ["."] [""] ghc.version}";
 in haskell.lib.buildStackProject {
   inherit ghc;
   name = "stackenv";
   buildInputs = (with pkgs;
     [ postgresql zlib openldap cyrus_sasl.dev
-    ]) ++ (with haskell.packages."ghc${builtins.replaceStrings ["."] [""] ghc.version}";
+    ]) ++ (with haskellPackages;
     [ yesod-bin
     ]);
 }