diff --git a/HACKING b/HACKING
index 473500aa5c..2bc008eae9 100644
--- a/HACKING
+++ b/HACKING
@@ -246,4 +246,4 @@ have done little to try to remove those warnings.
 If you do not have Flex installed, it can be downloaded from the
 following URL:
 
-   http://flex.sourceforge.net/
+    https://github.com/westes/flex