diff --git a/opal/opal.rb b/opal/opal.rb
index 8d690772a9..f19a599835 100644
--- a/opal/opal.rb
+++ b/opal/opal.rb
@@ -1,7 +1,7 @@
 require 'opal/base'
 require 'opal/mini'
 
-require 'corelib/kernel/format'
+#require 'corelib/kernel/format'
 require 'corelib/string/encoding'
 #require 'corelib/math'
 #require 'corelib/complex'