diff --git a/src/BeSimple/SoapCommon/Helper.php b/src/BeSimple/SoapCommon/Helper.php
index c33a9df7..1526720a 100644
--- a/src/BeSimple/SoapCommon/Helper.php
+++ b/src/BeSimple/SoapCommon/Helper.php
@@ -144,7 +144,7 @@ class Helper
     /**
      * Describing Media Content of Binary Data in XML namespace prefix.
      */
-    const PFX_XMLMIME = 'xmlmime';
+    const PFX_XMLMIME = 'xmime';
 
     /**
      * XML Schema namespace prefix.
@@ -218,4 +218,4 @@ public static function getSoapVersionFromNamespace($namespace)
             return SOAP_1_1;
         }
     }
-}
\ No newline at end of file
+}