diff --git a/sources/files/index.html b/sources/files/index.html
index a00287b..1ec6841 100644
--- a/sources/files/index.html
+++ b/sources/files/index.html
@@ -10,7 +10,7 @@
 <br>
 
 <p>As a reward, here is a random cat picture:</p>
-<p><img src="http://thecatapi.com/api/images/get?format=src&type=gif"></p>
+<p><img src="https://thecatapi.com/api/images/get?format=src&type=gif"></p>
 
 </body>
 </html>