diff --git a/package/gluon-config-mode-contact-info/luasrc/lib/gluon/config-mode/wizard/0500-contact-info.lua b/package/gluon-config-mode-contact-info/luasrc/lib/gluon/config-mode/wizard/0500-contact-info.lua
index 3b44773e8033da6d8715fac5eba046685e73a687..9341073441f864cb76e7a11e0d654042f80ebfa4 100644
--- a/package/gluon-config-mode-contact-info/luasrc/lib/gluon/config-mode/wizard/0500-contact-info.lua
+++ b/package/gluon-config-mode-contact-info/luasrc/lib/gluon/config-mode/wizard/0500-contact-info.lua
@@ -16,6 +16,7 @@ return function(form, uci)
 
 	local o = s:option(Value, "contact", pkg_i18n.translate("Contact info"), pkg_i18n.translate("e.g. E-mail or phone number"))
 	o.default = uci:get("gluon-node-info", owner, "contact")
+	o.datatype = 'minlength(1)'
 	o.optional = true
 	function o:write(data)
 		uci:set("gluon-node-info", owner, "contact", data)