diff --git a/README.asciidoc b/README.asciidoc
index 3e9cd56ae..192b7373f 100644
--- a/README.asciidoc
+++ b/README.asciidoc
@@ -499,4 +499,4 @@ http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
 
 https://en.wikipedia.org/wiki/C0_and_C1_control_codes
 
-http://vt100.net/
+https://vt100.net/