diff --git a/lib/oauth2.js b/lib/oauth2.js
index 835b327..3210171 100644
--- a/lib/oauth2.js
+++ b/lib/oauth2.js
@@ -74,6 +74,10 @@ exports.OAuth2.prototype._request= function(method, url, headers, post_body, acc
   }
   realHeaders['Host']= parsedUrl.host;
 
+  if (!realHeaders['User-Agent']) {
+    realHeaders['User-Agent'] = 'Node-oauth';
+  }
+
   realHeaders['Content-Length']= post_body ? Buffer.byteLength(post_body) : 0;
   if( access_token && !('Authorization' in realHeaders)) {
     if( ! parsedUrl.query ) parsedUrl.query= {};
diff --git a/tests/oauth2.js b/tests/oauth2.js
index 3eda163..d16a0e0 100644
--- a/tests/oauth2.js
+++ b/tests/oauth2.js
@@ -133,5 +133,29 @@ vows.describe('OAuth2').addBatch({
           oa.get("", {});
         }
       }
+    },
+    'When the user passes in the User-Agent in customHeaders': {
+      topic: new OAuth2("clientId", "clientSecret", undefined, undefined, undefined,
+          { 'User-Agent': '123Agent' }),
+      'When calling get': {
+        'we should see the User-Agent mixed into headers property in options passed to http-library' : function(oa) {
+          oa._executeRequest= function( http_library, options, callback ) {
+            assert.equal(options.headers["User-Agent"], "123Agent");
+          };
+          oa.get("", {});
+        }
+      }
+    },
+    'When the user does not pass in a User-Agent in customHeaders': {
+      topic: new OAuth2("clientId", "clientSecret", undefined, undefined, undefined,
+        undefined),
+      'When calling get': {
+        'we should see the default User-Agent mixed into headers property in options passed to http-library' : function(oa) {
+          oa._executeRequest= function( http_library, options, callback ) {
+            assert.equal(options.headers["User-Agent"], "Node-oauth");
+            };
+          oa.get("", {});
+        }
+      }
     }
 }).export(module);