diff --git a/lib/PeerManager.js b/lib/PeerManager.js
index c9f692446..99be6b306 100644
--- a/lib/PeerManager.js
+++ b/lib/PeerManager.js
@@ -1,5 +1,5 @@
 var imports         = require('soop').imports();
-var extend          = imports.extend || require('extend');
+var _               = imports._ || require('underscore');
 var log             = imports.log || require('../util/log');
 var bitcoreDefaults = imports.config || require('../config');
 var Connection      = imports.Connection || require ('./Connection');
@@ -12,7 +12,7 @@ GetAdjustedTime = imports.GetAdjustedTime || function () {
 
 function PeerManager(config) {
   // extend defaults with config
-  this.config = extend(true, config || {}, bitcoreDefaults);
+  this.config = _.extend(bitcoreDefaults, config || {});
   this.active = false;
   this.timer = null;
 
diff --git a/package.json b/package.json
index a4a03918d..3585c617b 100644
--- a/package.json
+++ b/package.json
@@ -71,8 +71,8 @@
     "brfs": "=1.0.0",
     "chai": "=1.9.1",
     "uglifyify": "=1.2.3",
-    "extend": "~1.2.1",
-    "async": "~0.2.10"
+    "async": "~0.2.10",
+    "underscore": "~1.6.0"
   },
   "devDependencies": {
     "grunt-contrib-watch": "~0.5.3",
diff --git a/test/test.PeerManager.js b/test/test.PeerManager.js
index ab6565d4c..d2c4ec829 100644
--- a/test/test.PeerManager.js
+++ b/test/test.PeerManager.js
@@ -30,6 +30,16 @@ describe('PeerManager', function() {
     pm.start();
     pm.stop.bind(pm).should.not.throw();
   });
+  it('should extend default config with passed config', function() {
+    var pm = new PeerManager({ 
+      proxy: { 
+        host: 'localhost', 
+        port: 9050 
+      } 
+    });
+    should.exist(pm.config.network);
+    should.exist(pm.config.proxy);
+  });
 });