diff --git a/TODO.md b/TODO.md
index e8d854f21..34ddb916c 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,5 +1,7 @@
 ## Before next release
 
+- fix warnings with OpenSSL 3.0
+
 ### Layered Sources
 
 - `zip_source_layered` should take ownership of lower source. (`zip_source_window` does not and is part of the public API, so keep it that way.) Document both.