diff --git a/Lib/encodings/rot_13.py b/Lib/encodings/rot_13.py
--- a/Lib/encodings/rot_13.py
+++ b/Lib/encodings/rot_13.py
@@ -101,13 +101,13 @@ rot13_map.update({
    0x0078: 0x006b,
    0x0079: 0x006c,
    0x007a: 0x006d,
 })
 
 ### Filter API
 
 def rot13(infile, outfile):
-    outfile.write(infile.read().encode('rot-13'))
+    outfile.write(codecs.encode(infile.read(), 'rot-13'))
 
 if __name__ == '__main__':
     import sys
     rot13(sys.stdin, sys.stdout)