diff --git a/api/current.xml b/api/current.xml
index 0f152d1..cbe47ff 100644
--- a/api/current.xml
+++ b/api/current.xml
@@ -108238,6 +108238,17 @@
  visibility="public"
 >
 </field>
+<field name="UNKNOWN"
+ type="java.lang.String"
+ transient="false"
+ volatile="false"
+ value="&quot;unknown&quot;"
+ static="true"
+ final="true"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</field>
 <field name="USER"
  type="java.lang.String"
  transient="false"
diff --git a/core/java/android/os/Build.java b/core/java/android/os/Build.java
index 5f6c9d6..4870b7c 100644
--- a/core/java/android/os/Build.java
+++ b/core/java/android/os/Build.java
@@ -21,7 +21,7 @@
  */
 public class Build {
     /** Value used for when a build property is unknown. */
-    private static final String UNKNOWN = "unknown";
+    public static final String UNKNOWN = "unknown";
 
     /** Either a changelist number, or a label like "M4-rc20". */
     public static final String ID = getString("ro.build.id");