diff --git a/core/src/main/java/org/apache/struts2/dispatcher/Dispatcher.java b/core/src/main/java/org/apache/struts2/dispatcher/Dispatcher.java
index 55707a4be..97e214921 100644
--- a/core/src/main/java/org/apache/struts2/dispatcher/Dispatcher.java
+++ b/core/src/main/java/org/apache/struts2/dispatcher/Dispatcher.java
@@ -88,7 +88,7 @@ public class Dispatcher {
      */
     public static final String REQUEST_POST_METHOD = "POST";
 
-    public static final String MULTIPART_FORM_DATA_REGEX = "^multipart\\/form-data(; boundary=[\\-a-zA-Z0-9]{1,70})?";
+    public static final String MULTIPART_FORM_DATA_REGEX = "^multipart/form-data(; boundary=[0-9a-zA-Z'()+_,\\-./:=?]{1,70})?";
 
     /**
      * Provide a thread local instance.