diff --git a/Lib/sunau.py b/Lib/sunau.py
index 4d07f43..5f50e8f 100644
--- a/Lib/sunau.py
+++ b/Lib/sunau.py
@@ -299,7 +299,7 @@
         self._nframeswritten = 0
         self._datawritten = 0
         self._datalength = 0
-        self._info = ''
+        self._info = b''
         self._comptype = 'ULAW' # default is U-law
 
     def setnchannels(self, nchannels):