diff --git a/httprl.module b/httprl.module
index 1053360..92e09c9 100644
--- a/httprl.module
+++ b/httprl.module
@@ -415,6 +415,7 @@ function httprl_request($url, $options = array()) {
   $content_length = httprl_strlen($options['data']);
   if ($content_length > 0 || $options['method'] == 'POST' || $options['method'] == 'PUT') {
     $options['headers']['Content-Length'] = $content_length;
+    $options['headers']['Content-Type'] = 'application/x-www-form-urlencoded';
   }
 
   // If the server URL has a user then attempt to use basic authentication.