diff --git a/README.txt b/README.txt
index e121928..7eb726c 100644
--- a/README.txt
+++ b/README.txt
@@ -30,7 +30,7 @@ fb = FileBuilder.build(__FILE__) do
 end
 
 fb.generate do |filename, class_builder|
-  File.open(filename, 'w') do |file|
+  File.open(filename, 'wb') do |file|
     file.write(class_builder.generate)
   end
 end
diff --git a/bin/bitec b/bin/bitec
index b8c6fef..7ad5429 100755
--- a/bin/bitec
+++ b/bin/bitec
@@ -18,5 +18,5 @@ end
 
 fb.generate do |filename, classbuilder|
   bytes = classbuilder.generate
-  File.open(filename, 'w') {|f| f.write(bytes)}
+  File.open(filename, 'wr') {|f| f.write(bytes)}
 end