diff --git a/mercurial/exchange.py b/mercurial/exchange.py
--- a/mercurial/exchange.py
+++ b/mercurial/exchange.py
@@ -1179,6 +1179,16 @@ def _pullbundle2(pullop):
             # make sure to always includes bookmark data when migrating
             # `hg incoming --bundle` to using this function.
             kwargs['listkeys'].append('bookmarks')
+
+    # If this is a full pull / clone and the server supports the clone bundles
+    # feature, tell the server whether we attempted a clone bundle. The
+    # presence of this flag indicates the client supports clone bundles. This
+    # will enable the server to treat clients that support clone bundles
+    # differently from those that don't.
+    if (pullop.remote.capable('clonebundles')
+        and pullop.heads is None and list(pullop.common) == [nullid]):
+        kwargs['cbattempted'] = pullop.clonebundleattempted
+
     if streaming:
         pullop.repo.ui.status(_('streaming all changes\n'))
     elif not pullop.fetch:
diff --git a/mercurial/wireproto.py b/mercurial/wireproto.py
--- a/mercurial/wireproto.py
+++ b/mercurial/wireproto.py
@@ -160,7 +160,8 @@ gboptsmap = {'heads':  'nodes',
              'obsmarkers': 'boolean',
              'bundlecaps': 'scsv',
              'listkeys': 'csv',
-             'cg': 'boolean'}
+             'cg': 'boolean',
+             'cbattempted': 'boolean'}
 
 # client side