diff --git a/Doc/tools/sgmlconv/conversion.xml b/Doc/tools/sgmlconv/conversion.xml
index 248c9c1..cff82ce 100644
--- a/Doc/tools/sgmlconv/conversion.xml
+++ b/Doc/tools/sgmlconv/conversion.xml
@@ -874,6 +874,7 @@
   <macro name="maketitle" outputname=""/>
   <macro name="noindent" outputname=""/>
   <macro name="protect" outputname=""/>
+  <macro name="textwidth"/>
   <macro name="renewcommand">
     <attribute name="macro"/>
     <attribute name="nargs" optional="yes"/>