diff --git a/zipstream/consts.py b/zipstream/consts.py
index 1c86fde..6823e2d 100644
--- a/zipstream/consts.py
+++ b/zipstream/consts.py
@@ -37,7 +37,7 @@
 DD_STRUCT64 = struct.Struct(b"<LQQ")
 DD_TUPLE = namedtuple("filecrc",
                       ("crc", "comp_size", "uncomp_size"))
-DD_MAGIC = b'\x08\x07\x4b\x50'
+DD_MAGIC = b'\x50\x4b\x07\x08'
 
 
 # central directory file header
diff --git a/zipstream/zipstream.py b/zipstream/zipstream.py
index 047adf0..baea177 100644
--- a/zipstream/zipstream.py
+++ b/zipstream/zipstream.py
@@ -5,6 +5,7 @@
 #
 import os
 import time
+import urllib
 import zlib
 from . import consts
 
@@ -113,6 +114,9 @@ def _create_file_struct(self, data):
         if 'file' in data:
             file_struct['src'] = data['file']
             file_struct['stype'] = 'f'
+        elif 'url' in data:
+            file_struct['src'] = data['url']
+            file_struct['stype'] = 'u'
         elif 'stream' in data:
             file_struct['src'] = data['stream']
             file_struct['stype'] = 's'
@@ -274,6 +278,14 @@ def data_generator(self, src, src_type):
                         break
                     yield part
             return
+        if src_type == 'u':
+            with urllib.request.urlopen(src) as fh:
+                while True:
+                    part = fh.read(self.chunksize)
+                    if not part:
+                        break
+                    yield part
+            return
 
     def _stream_single_file(self, file_struct):
         """