diff --git a/lib/agent.js b/lib/agent.js
index 606b2ebb..5f16ae3d 100644
--- a/lib/agent.js
+++ b/lib/agent.js
@@ -25,7 +25,11 @@ module.exports = TestAgent;
 function TestAgent(app, options) {
   if (!(this instanceof TestAgent)) return new TestAgent(app, options);
   if (typeof app === 'function') app = http.createServer(app);  // eslint-disable-line no-param-reassign
-  if (options) this._ca = options.ca;
+  if (options) {
+    this._ca = options.ca;
+    this._key = options.key;
+    this._cert = options.cert;
+  }
   Agent.call(this);
   this.app = app;
 }
@@ -41,6 +45,8 @@ methods.forEach(function(method) {
   TestAgent.prototype[method] = function(url, fn) {   // eslint-disable-line no-unused-vars
     var req = new Test(this.app, method.toUpperCase(), url);
     req.ca(this._ca);
+    req.cert(this._cert);
+    req.key(this._key);
 
     req.on('response', this._saveCookies.bind(this));
     req.on('redirect', this._saveCookies.bind(this));