diff --git a/ext/json/extconf.rb b/ext/json/extconf.rb
new file mode 100644
index 0000000000..8a99b6a5c8
--- /dev/null
+++ b/ext/json/extconf.rb
@@ -0,0 +1,3 @@
+require 'mkmf'
+
+create_makefile('json')