diff --git a/lib/KOReaderSync/KOReaderSyncClient.cpp b/lib/KOReaderSync/KOReaderSyncClient.cpp
index c99e43e8..f0183452 100644
--- a/lib/KOReaderSync/KOReaderSyncClient.cpp
+++ b/lib/KOReaderSync/KOReaderSyncClient.cpp
@@ -20,7 +20,8 @@ void addAuthHeaders(HTTPClient& http) {
   http.addHeader("x-auth-user", KOREADER_STORE.getUsername().c_str());
   http.addHeader("x-auth-key", KOREADER_STORE.getMd5Password().c_str());
 
-  // [FIXME] FB hack per mio CWA che non autentica con x-auth-user
+  // HTTP Basic Auth (RFC 7617) header. This is needed to support koreader sync server embedded in Calibre Web Automated
+  // (https://github.com/crocodilestick/Calibre-Web-Automated/blob/main/cps/progress_syncing/protocols/kosync.py)
   http.setAuthorization(KOREADER_STORE.getUsername().c_str(), KOREADER_STORE.getPassword().c_str());
 }