gistfile1

diff --git a/ext/json/ext/generator/extconf.rb b/ext/json/ext/generator/extconf.rb
index b0eab0d..149f22c 100644
--- a/ext/json/ext/generator/extconf.rb
+++ b/ext/json/ext/generator/extconf.rb
@@ -11,6 +11,10 @@ if CONFIG['CC'] =~ /gcc/
   #end
 end
 
-have_header("ruby/re.h") || have_header("re.h")
-have_header("ruby/encoding.h")
+if RUBY_VERSION < "1.9"
+  have_header("re.h")
+else
+  have_header("ruby/re.h")
+  have_header("ruby/encoding.h")
+end
 create_makefile 'json/ext/generator'