diff --git a/configure.ac b/configure.ac
index 606c736..68ce7d6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -122,7 +122,7 @@
 ])
 
 openssl=yes
-ssh1=no
+ssh1=yes
 AC_ARG_WITH([openssl],
 	[  --without-openssl       Disable use of OpenSSL; use only limited internal crypto **EXPERIMENTAL** ],
 	[  if test "x$withval" = "xno" ; then
@@ -147,6 +147,10 @@
 				AC_MSG_ERROR([Cannot enable SSH protocol 1 with OpenSSL disabled])
 			fi
 			ssh1=yes
+		elif test "x$withval" = "xno" ; then
+			ssh1=no
+		else
+			AC_MSG_ERROR([unknown --with-ssh1 argument])
 		fi
 	]
 )