diff --git a/findbugs-exclude-filter.xml b/findbugs-exclude-filter.xml
index 6b4ccad..fc07728 100644
--- a/findbugs-exclude-filter.xml
+++ b/findbugs-exclude-filter.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="iso-8859-1"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
    Licensed to the Apache Software Foundation (ASF) under one or more
    contributor license agreements.  See the NOTICE file distributed with
@@ -17,7 +17,9 @@
 -->
 
 <!-- ===================================================================== -->
-<FindBugsFilter>
+<FindBugsFilter xmlns="https://github.com/spotbugs/filter/3.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="https://github.com/spotbugs/filter/3.0.0 https://raw.githubusercontent.com/spotbugs/spotbugs/3.1.0/spotbugs/etc/findbugsfilter.xsd">
   <!-- Enable only high priority warnings -->
   <Match>
     <Priority value="2"/>
@@ -26,4 +28,11 @@
   <Match>
     <Priority value="3"/>
   </Match>
+
+  <Match>
+    <!-- Ignore bug on deprecated field we must keep for binary compatibility.  -->
+    <Class name="org.apache.commons.vfs2.provider.webdav4.Webdav4FileProvider" />
+    <Field name="AUTHENTICATOR_TYPES" />
+    <Bug pattern="MS_MUTABLE_ARRAY" />
+  </Match>
 </FindBugsFilter>