diff --git a/flake.nix b/flake.nix
index 1ec58bb..be3df0b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -17,11 +17,20 @@
     in inputs.flake-utils.lib.eachSystem systems (system:
       let
         pkgs = import nixpkgs { inherit system; };
+        gems = ruby-nix.lib pkgs {
+          name = "asciidoctor-foodogsquared-extensions";
+          ruby = pkgs.ruby_3_1;
+          gemset = ./gemset.nix;
+        };
       in
       {
         devShells.default =
           import ./shell.nix {
-            inherit pkgs ruby-nix;
+            inherit pkgs;
+            extraBuildInputs = [
+              gems.env
+              gems.ruby
+            ];
             extraPackages = [
               inputs.ruby-nix-bundix.packages."${system}".default
             ];
diff --git a/shell.nix b/shell.nix
index baf6927..c40b9d1 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,25 +1,18 @@
 { pkgs ? import <nixpkgs> { }
-, ruby-nix
 , extraPackages ? [ ]
 , extraBuildInputs ? [ ]
 }:
 
 with pkgs;
 
-let
-  gems = ruby-nix.lib pkgs {
-    name = "asciidoctor-foodogsquared-extensions";
-    ruby = ruby_3_1;
-    gemset = ./gemset.nix;
-  };
-in
 mkShell {
   buildInputs = [
-    gems.env
-    gems.ruby
+    # Dependencies for Nokogiri.
     pkg-config
     zlib
     libiconv
+
+    # Dependencies for rugged.
     libgit2
   ] ++ extraBuildInputs;