diff --git a/tool/pure_parser.rb b/tool/pure_parser.rb
index d07df681be..21c87cc5d6 100755
--- a/tool/pure_parser.rb
+++ b/tool/pure_parser.rb
@@ -1,11 +1,14 @@
 #!/usr/bin/ruby -pi.bak
 BEGIN {
+  # pathological setting
+  ENV['LANG'] = ENV['LC_MESSAGES'] = ENV['LC_ALL'] = 'C'
+
   require_relative 'lib/colorize'
 
   colorize = Colorize.new
   file = ARGV.shift
   begin
-    version = IO.popen(ARGV+%w[--version], &:read)
+    version = IO.popen(ARGV+%w[--version], "rb", &:read)
   rescue Errno::ENOENT
     abort "Failed to run `#{colorize.fail ARGV.join(' ')}'; You may have to install it."
   end