diff -r 139c18943d9b Lib/shutil.py
--- a/Lib/shutil.py	Sat Nov 14 08:54:30 2015 +0000
+++ b/Lib/shutil.py	Sat Nov 14 18:43:35 2015 +0800
@@ -677,8 +677,7 @@
                     zip_filename, base_dir)
 
     if not dry_run:
-        with zipfile.ZipFile(zip_filename, "w",
-                             compression=zipfile.ZIP_DEFLATED) as zf:
+        with zipfile.ZipFile(zip_filename, "w") as zf:
             path = os.path.normpath(base_dir)
             zf.write(path, path)
             if logger is not None:
@@ -692,7 +691,7 @@
                 for name in filenames:
                     path = os.path.normpath(os.path.join(dirpath, name))
                     if os.path.isfile(path):
-                        zf.write(path, path)
+                        zf.write(path, path, zipfile.ZIP_DEFLATED)
                         if logger is not None:
                             logger.info("adding '%s'", path)
 
diff -r 139c18943d9b Lib/zipfile.py
--- a/Lib/zipfile.py	Sat Nov 14 08:54:30 2015 +0000
+++ b/Lib/zipfile.py	Sat Nov 14 18:43:35 2015 +0800
@@ -1444,7 +1444,9 @@
             arcname += '/'
         zinfo = ZipInfo(arcname, date_time)
         zinfo.external_attr = (st[0] & 0xFFFF) << 16      # Unix attributes
-        if compress_type is None:
+        if isdir:
+            zinfo.compress_type = ZIP_STORED
+        elif compress_type is None:
             zinfo.compress_type = self.compression
         else:
             zinfo.compress_type = compress_type