1 files changed, 3 insertions, 3 deletions
diff --git a/mrbgems/mruby-io/mrblib/io.rb b/mrbgems/mruby-io/mrblib/io.rb
index f3c4de6fd..a6e3ef3de 100644
--- a/mrbgems/mruby-io/mrblib/io.rb
+++ b/mrbgems/mruby-io/mrblib/io.rb
@@ -226,12 +226,12 @@ class IO
     end
   end
 
-  def readline(arg = $/, limit = nil)
+  def readline(arg = "\n", limit = nil)
     case arg
     when String
       rs = arg
     when Fixnum
-      rs = $/
+      rs = "\n"
       limit = arg
     else
       raise ArgumentError
@@ -242,7 +242,7 @@ class IO
     end
 
     if rs == ""
-      rs = $/ + $/
+      rs = "\n\n"
     end
 
     array = []