diff --git a/pkgs/development/interpreters/ruby/ruby-19.nix b/pkgs/development/interpreters/ruby/ruby-19.nix
index b954d7e6bf0..6545ed720e6 100644
--- a/pkgs/development/interpreters/ruby/ruby-19.nix
+++ b/pkgs/development/interpreters/ruby/ruby-19.nix
@@ -32,7 +32,7 @@ stdenv.mkDerivation rec {
     ++ (op gdbmSupport gdbm)
     ++ (op yamlSupport libyaml);
 
-  enableParallelBuilding = true;
+  enableParallelBuilding = false;
     
   configureFlags = ["--enable-shared" "--enable-pthread"];