diff --git a/core/src/test/java/org/apache/struts2/interceptor/FileUploadInterceptorTest.java b/core/src/test/java/org/apache/struts2/interceptor/FileUploadInterceptorTest.java
index 9b67535..3e621b1 100644
--- a/core/src/test/java/org/apache/struts2/interceptor/FileUploadInterceptorTest.java
+++ b/core/src/test/java/org/apache/struts2/interceptor/FileUploadInterceptorTest.java
@@ -40,6 +40,7 @@
 import java.io.IOException;
 import java.net.URI;
 import java.net.URL;
+import java.nio.charset.StandardCharsets;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
@@ -244,7 +245,7 @@
     public void testNoContentMultipartRequest() throws Exception {
         MockHttpServletRequest req = new MockHttpServletRequest();
 
-        req.setCharacterEncoding("text/html");
+        req.setCharacterEncoding(StandardCharsets.UTF_8.name());
         req.setMethod("post");
         req.addHeader("Content-type", "multipart/form-data");
         req.setContent(null); // there is no content
@@ -265,7 +266,7 @@
 
     public void testSuccessUploadOfATextFileMultipartRequest() throws Exception {
         MockHttpServletRequest req = new MockHttpServletRequest();
-        req.setCharacterEncoding("text/html");
+        req.setCharacterEncoding(StandardCharsets.UTF_8.name());
         req.setMethod("post");
         req.addHeader("Content-type", "multipart/form-data; boundary=---1234");
 
@@ -322,7 +323,7 @@
         final String endline = "\r\n";
 
         MockHttpServletRequest req = new MockHttpServletRequest();
-        req.setCharacterEncoding("text/html");
+        req.setCharacterEncoding(StandardCharsets.UTF_8.name());
         req.setMethod("POST");
         req.addHeader("Content-type", "multipart/form-data; boundary=" + bondary);
         StringBuilder content = new StringBuilder(128);
@@ -371,7 +372,7 @@
 
     public void testMultipartRequestLocalizedError() throws Exception {
         MockHttpServletRequest req = new MockHttpServletRequest();
-        req.setCharacterEncoding("text/html");
+        req.setCharacterEncoding(StandardCharsets.UTF_8.name());
         req.setMethod("post");
         req.addHeader("Content-type", "multipart/form-data; boundary=---1234");