diff --git a/index.js b/index.js
index f71ecbf6a..8454bce5d 100644
--- a/index.js
+++ b/index.js
@@ -48,14 +48,16 @@ class Client extends EventEmitter {
       requestTimeout: 30000,
       sniffInterval: false,
       sniffOnStart: false,
-      ssl: null
+      ssl: null,
+      agent: null
     }, opts)
 
     this[kSelector] = new options.Selector()
     this[kSerializer] = new options.Serializer()
     this[kConnectionPool] = new options.ConnectionPool({
       selector: this[kSelector],
-      ssl: options.ssl
+      ssl: options.ssl,
+      agent: null
     })
 
     // Add the connections before initialize the Transport
diff --git a/lib/Connection.js b/lib/Connection.js
index a08765d8a..99d9f7be9 100644
--- a/lib/Connection.js
+++ b/lib/Connection.js
@@ -24,8 +24,7 @@ class Connection {
       keepAlive: true,
       keepAliveMsecs: 1000,
       maxSockets: Infinity,
-      maxFreeSockets: 256,
-      timeout: 60000
+      maxFreeSockets: 256
     }, opts.host.agent || opts.agent)
     this._agent = this.host.protocol === 'http:'
       ? new HttpAgent(agentOptions)
diff --git a/lib/ConnectionPool.js b/lib/ConnectionPool.js
index 7e16b5269..e6fbd446b 100644
--- a/lib/ConnectionPool.js
+++ b/lib/ConnectionPool.js
@@ -10,7 +10,8 @@ class ConnectionPool {
     this.alive = []
     this.dead = []
     this.selector = opts.selector
-    this.sll = opts.sll
+    this._ssl = opts.ssl
+    this._agent = opts.agent
     // the resurrect timeout is 60s
     // we multiply it by 2 because the resurrect formula is
     // `Math.pow(resurrectTimeout * 2, deadCount -1)`
@@ -143,12 +144,17 @@ class ConnectionPool {
     if (typeof opts === 'string') {
       opts = this.urlToHost(opts)
     }
-    Object.assign(opts, this.ssl)
+    if (opts.ssl == null) opts.ssl = this._ssl
+    if (opts.agent == null) opts.agent = this._agent
+
     const connection = new Connection(opts)
     debug('Adding a new connection', connection)
+    if (this.connections.has(connection.id)) {
+      throw new Error(`Connection with id '${connection.id} is already present`)
+    }
     this.connections.set(connection.id, connection)
     this.alive.push(connection.id)
-    return this
+    return connection
   }
 
   /**
diff --git a/lib/Transport.js b/lib/Transport.js
index 3c962f2df..6f30dc7c0 100644
--- a/lib/Transport.js
+++ b/lib/Transport.js
@@ -49,6 +49,7 @@ class Transport {
       params.headers['Content-Length'] = '' + Buffer.byteLength(params.body)
     }
 
+    params.timeout = params.timeout || this.requestTimeout
     this.emit('request', params)
     const request = connection.request(params, (err, response) => {
       if (err != null) {
@@ -61,7 +62,7 @@ class Transport {
 
         const error = err.message === 'Request timed out'
           ? new TimeoutError(err.message)
-          : ConnectionError(err.message)
+          : new ConnectionError(err.message)
 
         this.emit('error', error, params)
         return callback(error)
@@ -70,14 +71,19 @@ class Transport {
       var json = ''
       response.setEncoding('utf8')
       response.on('data', chunk => { json += chunk })
-      response.on('error', err => callback(err))
+      response.on('error', err => callback(new ConnectionError(err.message)))
       response.on('end', () => {
         this.connectionPool.markAlive(connection)
-        try {
-          var payload = this.serializer.deserialize(json)
-        } catch (err) {
-          this.emit('error', err)
-          return callback(err)
+        const contentType = response.headers['content-type']
+        if (contentType != null && contentType.indexOf('application/json') > -1) {
+          try {
+            var payload = this.serializer.deserialize(json)
+          } catch (err) {
+            this.emit('error', err)
+            return callback(err)
+          }
+        } else {
+          payload = json
         }
         const { statusCode } = response
         this.emit('response', params, { statusCode, payload })
@@ -89,9 +95,11 @@ class Transport {
       })
     })
 
-    return function requestAborter () {
-      request.abort()
-      debug('Request aborted', params)
+    return {
+      abort: () => {
+        request.abort()
+        debug('Request aborted', params)
+      }
     }
   }