diff --git a/lib/RELEASE-NOTES b/lib/RELEASE-NOTES
index a0537df5e8..43ab459fc4 100644
--- a/lib/RELEASE-NOTES
+++ b/lib/RELEASE-NOTES
@@ -146,6 +146,7 @@
 
 * The dependency on pplatex/dvipost was dropped.
 
+* The dependency on sgmltools was dropped, see DocBook 5 section.
 
 
 !!Known issues in version 2.4.0