diff --git a/luci-app-openmptcprouter/luasrc/view/openmptcprouter/wizard.htm b/luci-app-openmptcprouter/luasrc/view/openmptcprouter/wizard.htm
index 5224df408..ba31c9dd7 100644
--- a/luci-app-openmptcprouter/luasrc/view/openmptcprouter/wizard.htm
+++ b/luci-app-openmptcprouter/luasrc/view/openmptcprouter/wizard.htm
@@ -22,6 +22,9 @@
 		return true
 	end
 	function splitstring(inputstr, sep)
+		if inputstr == nil then
+			return ""
+		end
 		if sep == nil then
 			sep = "%s"
 		end