diff --git a/pkgs/development/interpreters/ruby/gem.nix b/pkgs/development/interpreters/ruby/gem.nix
index 07cfefeae62e..084d0fdb4662 100644
--- a/pkgs/development/interpreters/ruby/gem.nix
+++ b/pkgs/development/interpreters/ruby/gem.nix
@@ -18,7 +18,7 @@ stdenv.mkDerivation (attrs // {
   inherit ruby rubygems;
   inherit doCheck;
 
-  buildInputs = [ rubygems makeWrapper git ] ++ buildInputs;
+  buildInputs = [ ruby rubygems makeWrapper git ] ++ buildInputs;
 
   name = namePrefix + name;