diff --git a/tests/json_parser_test.rb b/tests/json_parser_test.rb
index f36e9c84..5f454eb1 100644
--- a/tests/json_parser_test.rb
+++ b/tests/json_parser_test.rb
@@ -4,6 +4,7 @@
 require 'stringio'
 require 'tempfile'
 require 'ostruct'
+require 'bigdecimal'
 
 class JSONParserTest < Test::Unit::TestCase
   include JSON