diff --git a/src/java/org/apache/poi/util/BitField.java b/src/java/org/apache/poi/util/BitField.java
index 90f60db9e..503284df3 100644
--- a/src/java/org/apache/poi/util/BitField.java
+++ b/src/java/org/apache/poi/util/BitField.java
@@ -25,7 +25,7 @@ package org.apache.poi.util;
  * @author Marc Johnson (mjohnson at apache dot org)
  * @author Andrew C. Oliver (acoliver at apache dot org)
  */
-
+@Interal
 public class BitField
 {
     private final int _mask;