diff --git a/README.md b/README.md
index e66db3c..253a811 100644
--- a/README.md
+++ b/README.md
@@ -289,7 +289,13 @@ These are the available config options for making requests. Only the `url` is re
 
   // `maxRedirects` defines the maximum number of redirects to follow in node.js.
   // If set to 0, no redirects will be followed.
-  maxRedirects: 5 // default
+  maxRedirects: 5, // default
+
+  // `httpAgent` and `httpsAgent` define a custom agent to be used when performing http
+  // and https requests, respectively, in node.js. This allows to configure options like
+  // `keepAlive` that are not enabled by default.
+  httpAgent: new http.Agent({ keepAlive: true }),
+  httpsAgent: new https.Agent({ keepAlive: true })
 }
 ```
 
diff --git a/lib/adapters/http.js b/lib/adapters/http.js
index 959bed9..21b02ae 100644
--- a/lib/adapters/http.js
+++ b/lib/adapters/http.js
@@ -61,13 +61,17 @@ module.exports = function httpAdapter(config) {
       var urlPassword = urlAuth[1] || '';
       auth = urlUsername + ':' + urlPassword;
     }
+
+    var isHttps = parsed.protocol === 'https:';
+    var agent = isHttps ? config.httpsAgent : config.httpAgent;
+
     var options = {
       hostname: parsed.hostname,
       port: parsed.port,
       path: buildURL(parsed.path, config.params, config.paramsSerializer).replace(/^\?/, ''),
       method: config.method,
       headers: headers,
-      agent: config.agent,
+      agent: agent,
       auth: auth
     };
 
@@ -79,12 +83,12 @@ module.exports = function httpAdapter(config) {
 
     var transport;
     if (config.maxRedirects === 0) {
-      transport = parsed.protocol === 'https:' ? https : http;
+      transport = isHttps ? https : http;
     } else {
       if (config.maxRedirects) {
         options.maxRedirects = config.maxRedirects;
       }
-      transport = parsed.protocol === 'https:' ? httpsFollow : httpFollow;
+      transport = isHttps ? httpsFollow : httpFollow;
     }
 
     // Create the request