diff --git a/README.md b/README.md
index 07610dc..6caece5 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Zlib-ladder
 
-Based on [aardio](www.aardio.com).
+Based on [aardio](https://www.aardio.com).
 
 + Development