diff --git a/Doc/lib/libweakref.tex b/Doc/lib/libweakref.tex
index 6ac7f36ff12..5e6e81933f8 100644
--- a/Doc/lib/libweakref.tex
+++ b/Doc/lib/libweakref.tex
@@ -2,6 +2,7 @@
          Weak references}
 
 \declaremodule{extension}{weakref}
+\modulesynopsis{Support for weak references and weak dictionaries.}
 \moduleauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
 \moduleauthor{Neil Schemenauer}{nas@arctrix.com}
 \moduleauthor{Martin von L\o"wis}{martin@loewis.home.cs.tu-berlin.de}