diff --git a/dvc/repo/brancher.py b/dvc/repo/brancher.py
index 14f27ec12..a07cf56e1 100644
--- a/dvc/repo/brancher.py
+++ b/dvc/repo/brancher.py
@@ -77,6 +77,7 @@ def brancher(  # noqa: E302
         from dvc.fs import GitFileSystem
 
         for sha, names in found_revs.items():
+            self.__dict__.pop("index", None)
             self.fs = GitFileSystem(scm=scm, rev=sha)
             self.root_dir = self.fs.path.join("/", *repo_root_parts)