diff --git a/config/lyxinclude.m4 b/config/lyxinclude.m4
index 53526a68f5..18e84dfcad 100644
--- a/config/lyxinclude.m4
+++ b/config/lyxinclude.m4
@@ -411,7 +411,7 @@ dnl Usage: LYX_USE_INCLUDED_BOOST : select if the included boost should
 dnl        be used.
 AC_DEFUN([LYX_USE_INCLUDED_BOOST],[
 	AC_ARG_WITH(included-boost,
-	    [  --without-included-boost  do not use the boost lib supplied with LyX],
+	    [  --without-included-boost  do not use the boost lib supplied with LyX, try to find one in the system directories - compilation will abort if nothing suitable is found],
 	    [lyx_cv_with_included_boost=$withval
 		AC_MSG_RESULT([$with_included_boost])],
 	    [lyx_cv_with_included_boost=yes])