diff --git a/ChangeLog b/ChangeLog
index e6fe47b6..48e9bf5b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2011-08-10  Giuseppe Scrivano  <gscrivano@gnu.org>
 
+	* configure.ac: Print usage string for --with-ssl.
+	Reported by: Karl Berry<karl@freefriends.org>
+
 	* configure.ac: Check for `gnutls_priority_set_direct' when gnutls is
 	used.
 	Reported by: Karl Berry<karl@freefriends.org>
diff --git a/configure.ac b/configure.ac
index 9b139d0c..d47303a5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -62,7 +62,8 @@ dnl Process features.
 dnl
 
 AC_ARG_WITH(ssl,
-[[  --without-ssl           disable SSL autodetection]])
+[[  --without-ssl           disable SSL autodetection
+  --with-ssl={gnutls,openssl} specify the SSL backend.  GNU TLS is the default.]])
 
 AC_ARG_ENABLE(opie,
 [  --disable-opie          disable support for opie or s/key FTP login],