diff --git a/Performance-tuning.md b/Performance-tuning.md
index 45e9730..ef055cb 100644
--- a/Performance-tuning.md
+++ b/Performance-tuning.md
@@ -33,7 +33,7 @@ In case collections with higher amount of items it can be that PROPFIND and REPO
 
 Precondition: file system supports mtime with ns proper (us is potentially also still enough, ms can turn risky)
 
-Background: it changes the cache content verification from SHA256(item) to filesystem metadata lookup mtime(item) size(item)
+Background: it changes the cache content verification from SHA256(item) to filesystem metadata lookup mtime(item)+size(item)
 
 ## filesystem_cache_folder + use_cache_subfolder_for_item