diff --git a/src/js/rulesAssistant.js b/src/js/rulesAssistant.js
index 2b4358a6f44120f6cdd684f89ca750ae7020ac88..77e6fdd53c089921faf0bb26dbc532fc9e8854c0 100644
--- a/src/js/rulesAssistant.js
+++ b/src/js/rulesAssistant.js
@@ -64,8 +64,6 @@ window.lastPregRule = function(slave, rules) {
 window.mergeRules = function(rules) {
 	if (rules.length === 0) {
 		return emptyDefaultRule().set;
-	} else if (rules.length === 1) {
-		return rules[0];
 	}
 
 	function isObject(o) {
@@ -98,7 +96,7 @@ window.mergeRules = function(rules) {
 		}
 	}
 
-	const combinedRule = rules[0];
+	const combinedRule = emptyDefaultRule().set;
 	const otherRules = rules.slice(1);
 
 	otherRules.forEach(rule => {