diff --git a/lib/configLoader.js b/lib/configLoader.js
index 0e093d3..2620c30 100644
--- a/lib/configLoader.js
+++ b/lib/configLoader.js
@@ -25,7 +25,7 @@ module.exports = {
 function mergeConfig(...configs) {
     logger.trace('merge all config')
 
-    return butil.assignWithValid({}, ...configs)
+    return butil.mergeWithValid({}, ...configs)
 }
 
 /**
diff --git a/lib/util.js b/lib/util.js
index 35e3e78..4a30f64 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -63,14 +63,14 @@ function assignPredict(older, newer) {
 
 function mergeWithValid(...sources) {
     sources.push(mergeCustomizer)
-    return _.assignWith(...sources)
+    return _.mergeWith(...sources)
 }
 
 function mergeCustomizer(older, newer) {
     if (Array.isArray(older)) {
         return older.concat(newer)
     } else if (_.isObject(older) && _.isObject(newer)) {
-        return assignWithValid(older, newer)
+        return mergeWithValid(older, newer)
     }
 
     return isEmpty(newer) ? older : newer