diff --git a/shell.nix b/shell.nix
index 0e50343..ed4e26b 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1 +1,5 @@
-{} @ attrs: (import ./. attrs).env
+attrs@
+  { compiler ? "ghc8101"
+  , withHoogle ? true
+  }:
+(import ./. attrs).env