diff -Nur ruby-2.3.0.orig/common.mk ruby-2.3.0/common.mk
--- ruby-2.3.0.orig/common.mk	2015-12-24 04:21:30.000000000 -0300
+++ ruby-2.3.0/common.mk	2016-01-01 00:58:13.284858253 -0300
@@ -15,7 +15,7 @@
 
 RUBYLIB       = $(PATH_SEPARATOR)
 RUBYOPT       = -
-RUN_OPTS      = --disable-gems
+RUN_OPTS      = --disable-gems -I$(srcdir)/../json-1.8.1/lib
 
 GEM_HOME =
 GEM_PATH =
@@ -781,8 +781,6 @@
 
 srcs-ext: $(EXT_SRCS)
 
-srcs-extra: $(srcdir)/ext/json/parser/parser.c
-
 LIB_SRCS = $(srcdir)/lib/unicode_normalize/tables.rb
 
 srcs-lib: $(LIB_SRCS)
@@ -875,11 +873,6 @@
 		Q=$(Q) ECHO=$(ECHO) RM="$(RM)" top_srcdir=../.. srcdir=. VPATH="$(PWD)" \
 		RUBY="$(BASERUBY)" PATH_SEPARATOR="$(PATH_SEPARATOR)"
 
-$(srcdir)/ext/json/parser/parser.c: $(srcdir)/ext/json/parser/parser.rl
-	$(ECHO) generating $@
-	$(Q) $(CHDIR) $(@D) && $(exec) $(MAKE) -f prereq.mk $(MFLAGS) \
-		Q=$(Q) ECHO=$(ECHO) top_srcdir=../../.. srcdir=. VPATH=../../.. BASERUBY="$(BASERUBY)"
-
 $(srcdir)/ext/rbconfig/sizeof/sizes.c: $(srcdir)/ext/rbconfig/sizeof/depend \
 		$(srcdir)/tool/generic_erb.rb $(srcdir)/template/sizes.c.tmpl $(srcdir)/configure.in
 	$(ECHO) generating $@
diff -Nur ruby-2.2.3.orig/ext/.document ruby-2.2.3/ext/.document
--- ruby-2.2.3.orig/ext/.document	2014-08-02 11:55:36.000000000 -0300
+++ ruby-2.2.3/ext/.document	2015-08-20 01:58:55.065621626 -0300
@@ -35,9 +35,6 @@
 io/nonblock/nonblock.c
 io/wait/lib
 io/wait/wait.c
-json/ext/generator/generator.c
-json/ext/parser/parser.c
-json/lib
 mathn/complex/complex.c
 mathn/rational/rational.c
 nkf/lib
diff -Nur ruby-2.3.0.orig/gems/bundled_gems ruby-2.3.0/gems/bundled_gems
--- ruby-2.3.0.orig/gems/bundled_gems	2015-12-22 14:30:22.000000000 -0300
+++ ruby-2.3.0/gems/bundled_gems	2016-01-01 00:59:51.899771661 -0300
@@ -4,3 +4,4 @@
 rake 10.4.2
 net-telnet 0.1.1
 did_you_mean 1.0.0
+json 1.8.1
diff -Nur ruby-2.3.0.orig/test/ruby/test_module.rb ruby-2.3.0/test/ruby/test_module.rb
--- ruby-2.3.0.orig/test/ruby/test_module.rb	2015-12-17 23:32:17.000000000 -0300
+++ ruby-2.3.0/test/ruby/test_module.rb	2016-01-01 00:58:15.961386861 -0300
@@ -211,7 +211,6 @@
 
     ancestors = Object.ancestors
     mixins = ancestors - [Object, Kernel, BasicObject]
-    mixins << JSON::Ext::Generator::GeneratorMethods::String if defined?(JSON::Ext::Generator::GeneratorMethods::String)
     assert_equal([Object, Kernel, BasicObject], ancestors - mixins)
     assert_equal([String, Comparable, Object, Kernel, BasicObject], String.ancestors - mixins)
   end
@@ -445,7 +444,6 @@
     assert_equal([Mixin], User.included_modules)
 
     mixins = Object.included_modules - [Kernel]
-    mixins << JSON::Ext::Generator::GeneratorMethods::String if defined?(JSON::Ext::Generator::GeneratorMethods::String)
     assert_equal([Kernel], Object.included_modules - mixins)
     assert_equal([Comparable, Kernel], String.included_modules - mixins)
   end