diff --git a/bitbake/lib/bb/fetch2/git.py b/bitbake/lib/bb/fetch2/git.py
index bcc0da5..5efdfa9 100644
--- a/bitbake/lib/bb/fetch2/git.py
+++ b/bitbake/lib/bb/fetch2/git.py
@@ -123,7 +123,8 @@ class Git(FetchMethod):
         for name in ud.names:
             # Ensure anything that doesn't look like a sha256 checksum/revision is translated into one
             if not ud.revisions[name] or len(ud.revisions[name]) != 40  or (False in [c in "abcdef0123456789" for c in ud.revisions[name]]):
-                ud.branches[name] = ud.revisions[name]
+                if ud.revisions[name]:
+                    ud.branches[name] = ud.revisions[name]
                 ud.revisions[name] = self.latest_revision(ud.url, ud, d, name)
 
         gitsrcname = '%s%s' % (ud.host.replace(':','.'), ud.path.replace('/', '.'))