diff --git a/pkgs/development/interpreters/ruby/ruby-19.nix b/pkgs/development/interpreters/ruby/ruby-19.nix
index 6545ed720e6..638aeab11ca 100644
--- a/pkgs/development/interpreters/ruby/ruby-19.nix
+++ b/pkgs/development/interpreters/ruby/ruby-19.nix
@@ -19,7 +19,7 @@ stdenv.mkDerivation rec {
   
   src = fetchurl {
     url = "ftp://ftp.ruby-lang.org/pub/ruby/1.9/${name}.tar.bz2";
-    sha256 = "1ymq5lhp3fz0j3cs65521aihcnivbfrn76in900ccxd0msgfmld9";
+    sha256 = "0w1avj8qfskvkgvrjxxc1cxjm14bf1v60ipvcl5q3zpn9k14k2cx";
   };
 
   # Have `configure' avoid `/usr/bin/nroff' in non-chroot builds.
@@ -32,8 +32,9 @@ stdenv.mkDerivation rec {
     ++ (op gdbmSupport gdbm)
     ++ (op yamlSupport libyaml);
 
-  enableParallelBuilding = false;
-    
+  enableParallelBuilding = true;
+  patches = [ ./ruby19-parallel-install.patch ];
+
   configureFlags = ["--enable-shared" "--enable-pthread"];
 
   installFlags = stdenv.lib.optionalString docSupport "install-doc";
@@ -50,7 +51,7 @@ stdenv.mkDerivation rec {
   passthru = rec {
     majorVersion = "1.9";
     minorVersion = "3";
-    patchLevel = "194";
+    patchLevel = "429";
     libPath = "lib/ruby/${majorVersion}";
     gemPath = "lib/ruby/gems/${majorVersion}";
   };
diff --git a/pkgs/development/interpreters/ruby/ruby19-parallel-install.patch b/pkgs/development/interpreters/ruby/ruby19-parallel-install.patch
new file mode 100644
index 00000000000..bb806350873
--- /dev/null
+++ b/pkgs/development/interpreters/ruby/ruby19-parallel-install.patch
@@ -0,0 +1,15 @@
+Index: ruby-1.9.3-p392/lib/mkmf.rb
+===================================================================
+--- ruby-1.9.3-p392.orig/lib/mkmf.rb
++++ ruby-1.9.3-p392/lib/mkmf.rb
+@@ -2039,8 +2039,8 @@ static: $(STATIC_LIB)#{$extout ? " insta
+       end
+       for f in files
+         dest = "#{dir}/#{File.basename(f)}"
+-        mfile.print("install-rb#{sfx}: #{dest} #{dir}\n")
+-        mfile.print("#{dest}: #{f}\n")
++        mfile.print("install-rb#{sfx}: #{dest}\n")
++        mfile.print("#{dest}: #{f} #{timestamp_file(dir)}\n")
+         mfile.print("\t$(Q) $(#{$extout ? 'COPY' : 'INSTALL_DATA'}) #{f} $(@D#{sep})\n")
+         if defined?($installed_list) and !$extout
+           mfile.print("\t@echo #{dest}>>$(INSTALLED_LIST)\n")