diff --git a/doc/src/sgml/external-projects.sgml b/doc/src/sgml/external-projects.sgml
index a9e8329125b..f42137ff268 100644
--- a/doc/src/sgml/external-projects.sgml
+++ b/doc/src/sgml/external-projects.sgml
@@ -190,7 +190,7 @@
PL/R
R
- http://www.joeconway.com/plr/
+ http://www.joeconway.com/plr.html