diff --git a/src/Monolog/Handler/AmqpHandler.php b/src/Monolog/Handler/AmqpHandler.php
index 833d72f9..8f0a2bab 100644
--- a/src/Monolog/Handler/AmqpHandler.php
+++ b/src/Monolog/Handler/AmqpHandler.php
@@ -65,7 +65,7 @@ class AmqpHandler extends AbstractProcessingHandler
                 0,
                 array(
                     'delivery_mode' => 2,
-                    'Content-type' => 'application/json',
+                    'content_type' => 'application/json',
                 )
             );
         } else {