diff --git a/overlay/default.nix b/overlay/default.nix
index 4d530172..d3c9cbf8 100644
--- a/overlay/default.nix
+++ b/overlay/default.nix
@@ -1,11 +1,7 @@
 final: prev:
 
 {
-
   bmxd = prev.callPackage ./bmxd.nix { };
 
   pile = prev.callPackage ./pile.nix { };
-
-  # Cut down build time of a Nix-2.4 dependency
-  mdbook = prev.mdbook.overrideAttrs (oa: { doCheck = false; });
 }