diff --git a/pkgs/development/ruby-modules/gem/default.nix b/pkgs/development/ruby-modules/gem/default.nix
index 7ba8c70a98059..649d33c464617 100644
--- a/pkgs/development/ruby-modules/gem/default.nix
+++ b/pkgs/development/ruby-modules/gem/default.nix
@@ -35,6 +35,7 @@ lib.makeOverridable (
 , namePrefix ? (let
     rubyName = builtins.parseDrvName ruby.name;
   in "${rubyName.name}${rubyName.version}-")
+, nativeBuildInputs ? []
 , buildInputs ? []
 , meta ? {}
 , patches ? []
@@ -87,11 +88,15 @@ stdenv.mkDerivation ((builtins.removeAttrs attrs ["source"]) // {
   inherit dontStrip;
   inherit type;
 
-  buildInputs = [
+  nativeBuildInputs = [
     ruby makeWrapper
   ] ++ lib.optionals (type == "git") [ gitMinimal ]
     ++ lib.optionals (type != "gem") [ bundler ]
-    ++ lib.optional stdenv.isDarwin darwin.libobjc
+    ++ nativeBuildInputs;
+
+  buildInputs = [
+    ruby
+  ] ++ lib.optionals stdenv.isDarwin [ darwin.libobjc ]
     ++ buildInputs;
 
   #name = builtins.trace (attrs.name or "no attr.name" ) "${namePrefix}${gemName}-${version}";