diff --git a/PYTHON-MANIFEST.in b/PYTHON-MANIFEST.in
index 544fefbc487..f3ef08c8263 100644
--- a/PYTHON-MANIFEST.in
+++ b/PYTHON-MANIFEST.in
@@ -8,6 +8,7 @@ graft third_party/address_sorting
 graft third_party/boringssl
 graft third_party/cares
 graft third_party/nanopb
+graft third_party/upb
 graft third_party/zlib
 include src/python/grpcio/_parallel_compile_patch.py
 include src/python/grpcio/_spawn_patch.py