diff --git a/subcmds/init.py b/subcmds/init.py
index bb7187d..b260ec0 100644
--- a/subcmds/init.py
+++ b/subcmds/init.py
@@ -111,6 +111,9 @@
                  dest='archive', action='store_true',
                  help='checkout an archive instead of a git repository for '
                       'each project. See git archive.')
+    g.add_option('--submodules',
+                 dest='submodules', action='store_true',
+                 help='sync any submodules associated with the manifest repo')
     g.add_option('-g', '--groups',
                  dest='groups', default='default',
                  help='restrict manifest projects to ones with specified '
@@ -236,10 +239,13 @@
               'in another location.', file=sys.stderr)
         sys.exit(1)
 
+    if opt.submodules:
+      m.config.SetString('repo.submodules', 'true')
+
     if not m.Sync_NetworkHalf(is_new=is_new, quiet=opt.quiet,
         clone_bundle=not opt.no_clone_bundle,
         current_branch_only=opt.current_branch_only,
-        no_tags=opt.no_tags):
+        no_tags=opt.no_tags, submodules=opt.submodules):
       r = m.GetRemote(m.remote.name)
       print('fatal: cannot obtain manifest %s' % r.url, file=sys.stderr)
 
@@ -253,7 +259,7 @@
       m.MetaBranchSwitch()
 
     syncbuf = SyncBuffer(m.config)
-    m.Sync_LocalHalf(syncbuf)
+    m.Sync_LocalHalf(syncbuf, submodules=opt.submodules)
     syncbuf.Finish()
 
     if is_new or m.CurrentBranch is None:
diff --git a/subcmds/sync.py b/subcmds/sync.py
index 8e8529e..82056f3 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -723,11 +723,12 @@
       mp.Sync_NetworkHalf(quiet=opt.quiet,
                           current_branch_only=opt.current_branch_only,
                           no_tags=opt.no_tags,
-                          optimized_fetch=opt.optimized_fetch)
+                          optimized_fetch=opt.optimized_fetch,
+                          submodules=self.manifest.HasSubmodules)
 
     if mp.HasChanges:
       syncbuf = SyncBuffer(mp.config)
-      mp.Sync_LocalHalf(syncbuf)
+      mp.Sync_LocalHalf(syncbuf, submodules=self.manifest.HasSubmodules)
       if not syncbuf.Finish():
         sys.exit(1)
       self._ReloadManifest(manifest_name)