diff --git a/XML/RPC2/Util/HTTPRequest.php b/XML/RPC2/Util/HTTPRequest.php
index 74541e1..31a3a23 100644
--- a/XML/RPC2/Util/HTTPRequest.php
+++ b/XML/RPC2/Util/HTTPRequest.php
@@ -42,7 +42,9 @@
 // dependencies {{{
 require_once 'XML/RPC2/Exception.php';
 require_once 'XML/RPC2/Client.php';
-require_once 'HTTP/Request2.php';
+if (!class_exists('HTTP_Request2', true)) {
+    require_once 'HTTP/Request2.php';
+}
 // }}}
 
 /**
diff --git a/composer.json b/composer.json
index 4713d04..e268bf3 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
     "require": {
         "php": ">=5.2.0",
         "pear/pear_exception": "^1.0.0",
-        "pear/http_request2": "^2.3.0"
+        "pear/http_request2": "^2.4.0"
     },
     "require-dev": {
         "phpunit/phpunit": "*"