diff --git a/shell.nix b/shell.nix
index 3df6678197..9902d2bd73 100644
--- a/shell.nix
+++ b/shell.nix
@@ -65,6 +65,9 @@ let
     # note: niv manages its own nixpkgs so it doesn't need pkgs.callPackage. Do
     # `cachix use niv` to get cached builds!
     (import sources.niv { }).niv
+
+    # tools for development environment
+    less
   ];
 in pkgs.mkShell {
   buildInputs = inputs ++ darwinInputs ++ linuxInputs;