Issue #7156 has been updated by ko1 (Koichi Sasada). Target version changed from 2.0.0 to next minor No feedback. ---------------------------------------- Bug #7156: Invalid byte sequence in US-ASCII when using URI from std lib https://bugs.ruby-lang.org/issues/7156#change-36365 Author: t0d0r (Todor Dragnev) Status: Feedback Priority: Normal Assignee: Category: lib Target version: next minor ruby -v: 1.9.3 Invalid byte sequence in US-ASCII on ruby 1.9.3 I receive that error when trying to open url with bulgarian text (utf-8: "??????§à??§Ú??"). It seems that the problem is in uri/common.rb from ruby standard library... adding str.force_encoding(Encoding::BINARY) to following method fix the problem class URI::Parser def escape(str, unsafe = @regexp[:UNSAFE]) unless unsafe.kind_of?(Regexp) # perhaps unsafe is String object unsafe = Regexp.new("[#{Regexp.quote(unsafe)}]", false) end str.force_encoding(Encoding::BINARY) # FIX str.gsub(unsafe) do us = $& tmp = '' us.each_byte do |uc| tmp << sprintf('%%%02X', uc) end tmp end.force_encoding(Encoding::US_ASCII) end end One more suggestion - maybe US_ASCII must be replaced to Encoding::BINARY too? -- http://bugs.ruby-lang.org/