Index: paste/paste/gzipper.py
===================================================================
--- paste/paste/gzipper.py	(revision 7040)
+++ paste/paste/gzipper.py	(working copy)
@@ -62,6 +62,7 @@
             self.compressible = False
         if self.compressible:
             headers.append(('content-encoding', 'gzip'))
+            headers.append(('vary', 'Accept-Encoding'))
         remove_header(headers, 'content-length')
         self.headers = headers
         self.status = status