diff --git a/Doc/lib/libsys.tex b/Doc/lib/libsys.tex
index 946ff1d..3b81384 100644
--- a/Doc/lib/libsys.tex
+++ b/Doc/lib/libsys.tex
@@ -365,7 +365,7 @@
 
   A program is free to modify this list for its own purposes.
 
-  \versionchanged[Unicode strings are no longer ignored.]{2.3}
+  \versionchanged[Unicode strings are no longer ignored]{2.3}
 \end{datadesc}
 
 \begin{datadesc}{platform}