diff --git a/dangerzone/updater/signatures.py b/dangerzone/updater/signatures.py
index 10f9699..8711a6c 100644
--- a/dangerzone/updater/signatures.py
+++ b/dangerzone/updater/signatures.py
@@ -389,6 +389,8 @@ def store_signatures(signatures: list[Dict], image_digest: str, pubkey: str) ->
         )
         json.dump(signatures, f)
 
+    write_log_index(get_log_index_from_signatures(signatures))
+
 
 def verify_local_image(image: str, pubkey: str) -> bool:
     """