Index: Lib/urllib/robotparser.py
===================================================================
--- Lib/urllib/robotparser.py	(revision 64891)
+++ Lib/urllib/robotparser.py	(working copy)
@@ -60,7 +60,10 @@
             elif err.code >= 400:
                 self.allow_all = True
         else:
-            self.parse(f.read().splitlines())
+            filetext = f.read()
+            if isinstance(filetext, bytes):
+                filetext = filetext.decode('utf-8')
+            self.parse(filetext.splitlines())
 
     def _add_entry(self, entry):
         if "*" in entry.useragents: