diff --git a/src/main/java/org/apache/commons/fileupload/util/mime/Base64Decoder.java b/src/main/java/org/apache/commons/fileupload/util/mime/Base64Decoder.java
index e452166..387bf76 100644
--- a/src/main/java/org/apache/commons/fileupload/util/mime/Base64Decoder.java
+++ b/src/main/java/org/apache/commons/fileupload/util/mime/Base64Decoder.java
@@ -44,7 +44,7 @@
     /*
      * set up the decoding table.
      */
-    protected final byte[] decodingTable = new byte[256];
+    private final byte[] decodingTable = new byte[256];
 
     protected void initialiseDecodingTable() {
         for (int i = 0; i < encodingTable.length; i++) {