diff --git a/lib/pull-request.js b/lib/pull-request.js
index 8a57996..9206774 100644
--- a/lib/pull-request.js
+++ b/lib/pull-request.js
@@ -70,8 +70,13 @@ PullRequest.prototype.setExport = function (callback) {
 }
 
 PullRequest.prototype.getDiff = function (callback) {
+    var req = {};
+    req.url = this.data.diff_url;
+    if (process.env.http_proxy) {
+        req.proxy = process.env.http_proxy;
+    }
 
-    request(this.data.diff_url, function (err, res, body) {
+    request(req, function (err, res, body) {
         if (err) return callback(err);
         this.exports.diff = body;
         callback(null, body);
diff --git a/lib/util/github.js b/lib/util/github.js
index 9b20c52..ec21d16 100644
--- a/lib/util/github.js
+++ b/lib/util/github.js
@@ -41,6 +41,9 @@ var github = function (path, options, callback) {
         else req.body = JSON.stringify(options);
     }
 
+    if (process.env.http_proxy) {
+        req.proxy = process.env.http_proxy;
+    }
     req.url     = 'https://api.github.com' + path;
     req.json    = true;
     req.method  = method;