--- a/plugins/mod_tombstones.lua	Mon Jul 17 00:37:44 2023 +0200
+++ b/plugins/mod_tombstones.lua	Mon Jul 17 01:38:54 2023 +0200
@@ -8,7 +8,7 @@
 -- Using a map store as key-value store so that removal of all user data
 -- does not also remove the tombstone, which would defeat the point
 local graveyard = module:open_store(nil, "map");
-local graveyard_cache = require "prosody.util.cache".new(module:get_option_number("tombstone_cache_size", 1024));
+local graveyard_cache = require "prosody.util.cache".new(module:get_option_integer("tombstone_cache_size", 1024, 1));
 
 local ttl = module:get_option_period("user_tombstone_expiry", nil);
 -- Keep tombstones forever by default