AX_SUBMODULE: mention default type of library to use

diff --git a/m4/ax_submodule.m4 b/m4/ax_submodule.m4
index cfb4414..272fa59 100644 (file)
--- a/m4/ax_submodule.m4
+++ b/m4/ax_submodule.m4
@@ -3,7 +3,7 @@ AC_DEFUN([AX_SUBMODULE],
 
 AC_ARG_WITH($1,
        [AS_HELP_STRING([--with-$1=$2],
-                       [Which $1 to use])])
+                       [Which $1 to use [default=$3]])])
 case "system" in
 $2)
        AC_ARG_WITH($1_prefix,