diff --git a/tools/uncompressedsize.py b/tools/uncompressedsize.py
index f326c4d3d..0b0d76766 100644
--- a/tools/uncompressedsize.py
+++ b/tools/uncompressedsize.py
@@ -102,4 +102,5 @@ if __name__ == "__main__":
   logging.basicConfig(level=logging.DEBUG)
   logging.getLogger('boto').setLevel(logging.CRITICAL)
 
+  backfill_sizes_from_json()
   backfill_sizes_from_data()