diff --git a/src/cf/kerberos.m4 b/src/cf/kerberos.m4
index b9b2294ebf..f0bed24e39 100644
--- a/src/cf/kerberos.m4
+++ b/src/cf/kerberos.m4
@@ -37,7 +37,7 @@ fi
 
 AC_ARG_WITH([krb5], [--with-krb5 Support for Kerberos 5 (manual configuration)])
 
-if test X$with_krb5 = Xyes; then
+if test X$with_krb5 != X; then
         if test X$conf_krb5 = XYES; then
 		AC_MSG_ERROR([--with-krb5-config and --with-krb5 are mutually exclusive, choose only one])
 	fi