diff --git a/by-topic/Prolog/README.md b/by-topic/Prolog/README.md
index d6dca66..2331152 100644
--- a/by-topic/Prolog/README.md
+++ b/by-topic/Prolog/README.md
@@ -18,7 +18,7 @@
 
 [Prolog Tutorial \-- 2.5 (wayback)](https://web.archive.org/web/20120203025542/http://www.csupomona.edu/~jrfisher/www/prolog_tutorial/2_5.html) ★
 
-[Prolog Guide - Data Structures](http://kti.ms.mff.cuni.cz/~bartak/prolog/data_struct.html) ★
+[Prolog Guide - Data Structures](https://web.archive.org/web/20230930131407/http://kti.ms.mff.cuni.cz/~bartak/prolog/data_struct.html) ★
 
 [Parsing in Prolog](https://www2.cs.sfu.ca/~cameron/Teaching/383/DCG.html) ★