Index: Lib/zipfile.py
===================================================================
--- Lib/zipfile.py	(revision 55850)
+++ Lib/zipfile.py	(working copy)
@@ -252,12 +252,13 @@
             self.extract_version = max(45, self.extract_version)
             self.create_version = max(45, self.extract_version)
 
+        filename = str(self.filename)
         header = struct.pack(structFileHeader, stringFileHeader,
                  self.extract_version, self.reserved, self.flag_bits,
                  self.compress_type, dostime, dosdate, CRC,
                  compress_size, file_size,
-                 len(self.filename), len(extra))
-        return header + self.filename + extra
+                 len(filename), len(extra))
+        return header + filename + extra
 
     def _decodeExtra(self):
         # Try to decode the extra field.
Index: Lib/test/test_zipfile.py
===================================================================
--- Lib/test/test_zipfile.py	(revision 55850)
+++ Lib/test/test_zipfile.py	(working copy)
@@ -515,6 +515,11 @@
         # and report that the first file in the archive was corrupt.
         self.assertRaises(RuntimeError, zipf.testzip)
 
+    def testUnicodeFilenames(self):
+        zf = zipfile.ZipFile(TESTFN, "w")
+        zf.writestr(u"foo.txt", "Test for unicode filename")
+        zf.close()
+
     def tearDown(self):
         support.unlink(TESTFN)
         support.unlink(TESTFN2)