--- a/doc/whatis.texi
+++ b/doc/whatis.texi
@@ -35,10 +35,11 @@ services can authenticate each other.
 @end macro
 @end ifinfo
 
-@tex
-@def@xsub#1{$_{#1}$}
-@global@let@sub=@xsub
-@end tex
+@iftex
+@macro sub{arg}
+@textsubscript{\arg\}
+@end macro
+@end iftex
 
 @ifhtml
 @macro sub{arg}
--- a/doc/win2k.texi
+++ b/doc/win2k.texi
@@ -311,4 +311,5 @@ Other useful programs include these:
 
 @itemize @bullet
 @item pwdump2
-@uref{http://www.bindview.com/Support/RAZOR/Utilities/Windows/pwdump2_readme.cfm}@end itemize
+@uref{http://www.bindview.com/Support/RAZOR/Utilities/Windows/pwdump2_readme.cfm}
+@end itemize