README.md: use HTML URL, not PHP

diff --git a/README.md b/README.md
index 8d70bf0..ba64e18 100644 (file)
--- a/README.md
+++ b/README.md
@@ -376,7 +376,7 @@ See Also
 
 The CDSChecker project page:
 
->   <http://demsky.eecs.uci.edu/c11modelchecker.php>
+>   <http://demsky.eecs.uci.edu/c11modelchecker.html>
 
 The CDSChecker source and accompanying benchmarks on Gitweb: