diff --git a/icu4j/src/com/ibm/icu/dev/test/util/TestUtilities.java b/icu4j/src/com/ibm/icu/dev/test/util/TestUtilities.java
index 1c1ccb6af65..d7f32b1b023 100644
--- a/icu4j/src/com/ibm/icu/dev/test/util/TestUtilities.java
+++ b/icu4j/src/com/ibm/icu/dev/test/util/TestUtilities.java
@@ -107,7 +107,7 @@ public class TestUtilities extends TestFmwk {
         };
         
         logln("Trying Compose");
-        UnicodeMap composed = ((UnicodeMap)scripts.clone()).composeWith(map1, composer);
+        UnicodeMap composed = ((UnicodeMap)scripts.cloneAsThawed()).composeWith(map1, composer);
         Object last = "";
         for (int i = 0; i < 0x10FFFF; ++i) {
         	Object comp = composed.getValue(i);
diff --git a/icu4j/src/com/ibm/icu/dev/test/util/UnicodeMap.java b/icu4j/src/com/ibm/icu/dev/test/util/UnicodeMap.java
index 3e1e2b8e52f..7ec67463b77 100644
--- a/icu4j/src/com/ibm/icu/dev/test/util/UnicodeMap.java
+++ b/icu4j/src/com/ibm/icu/dev/test/util/UnicodeMap.java
@@ -35,6 +35,7 @@ import com.ibm.icu.impl.Utility;
 import com.ibm.icu.text.UTF16;
 import com.ibm.icu.text.UnicodeSet;
 import com.ibm.icu.text.UnicodeSetIterator;
+import com.ibm.icu.util.Freezable;
 /**
  * Class for mapping Unicode characters to values
  * Much smaller storage than using HashMap, and much faster and more compact than
@@ -42,7 +43,7 @@ import com.ibm.icu.text.UnicodeSetIterator;
  * @author Davis
  */
 
-public final class UnicodeMap implements Cloneable, Lockable, Externalizable {
+public final class UnicodeMap implements Cloneable, Freezable, Externalizable {
     static final boolean ASSERTIONS = false;
     static final long GROWTH_PERCENT = 200; // 100 is no growth!
     static final long GROWTH_GAP = 10; // extra bump!
@@ -98,7 +99,7 @@ public final class UnicodeMap implements Cloneable, Lockable, Externalizable {
     /**
      * Standard clone. Warning, as with Collections, does not do deep clone.
      */
-    public Object clone() {
+    public Object cloneAsThawed() {
         UnicodeMap that = new UnicodeMap();
         that.length = length;
         that.transitions = (int[]) transitions.clone();
@@ -606,7 +607,7 @@ public final class UnicodeMap implements Cloneable, Lockable, Externalizable {
 	/* (non-Javadoc)
 	 * @see com.ibm.icu.dev.test.util.Lockable#isLocked()
 	 */
-	public boolean isLocked() {
+	public boolean isFrozen() {
 		// TODO Auto-generated method stub
 		return locked;
 	}
@@ -614,7 +615,7 @@ public final class UnicodeMap implements Cloneable, Lockable, Externalizable {
 	/* (non-Javadoc)
 	 * @see com.ibm.icu.dev.test.util.Lockable#lock()
 	 */
-	public Object lock() {
+	public Object freeze() {
 		locked = true;
 		return this;
 	}
diff --git a/icu4j/src/com/ibm/icu/dev/test/util/UnicodeProperty.java b/icu4j/src/com/ibm/icu/dev/test/util/UnicodeProperty.java
index 5723e85a57c..0477345d109 100644
--- a/icu4j/src/com/ibm/icu/dev/test/util/UnicodeProperty.java
+++ b/icu4j/src/com/ibm/icu/dev/test/util/UnicodeProperty.java
@@ -325,7 +325,7 @@ Name: Unicode_1_Name
      * @return the unicode map
      */
     public UnicodeMap getUnicodeMap(boolean getShortest) {
-    	if (!getShortest) return (UnicodeMap) getUnicodeMap_internal().clone();
+    	if (!getShortest) return (UnicodeMap) getUnicodeMap_internal().cloneAsThawed();
         UnicodeMap result = new UnicodeMap();
         for (int i = 0; i <= 0x10FFFF; ++i) {
             //if (DEBUG && i == 0x41) System.out.println(i + "\t" + getValue(i));
diff --git a/icu4j/src/com/ibm/icu/util/Freezable.java b/icu4j/src/com/ibm/icu/util/Freezable.java
new file mode 100644
index 00000000000..63f8a66dfd7
--- /dev/null
+++ b/icu4j/src/com/ibm/icu/util/Freezable.java
@@ -0,0 +1,34 @@
+/*
+ ******************************************************************************
+ * Copyright (C) 2005, International Business Machines Corporation and        *
+ * others. All Rights Reserved.                                               *
+ ******************************************************************************
+*/
+package com.ibm.icu.util;
+
+/**
+ * Provides a flexible mechanism for controlling access, without requiring that a class be immutable.
+ * Once locked, an object can never be unlocked, so it is thread-safe from that point onward.
+ * The implementation of both methods must be synchronized.
+ * Once the object has been locked, it must guarantee that no changes can be made to it.
+ * Any attempt to alter it must raise an UnsupportedOperationException exception.
+ * This means that when the object returns internal objects,
+ * or if anyone has references to those internal objects, that those internal objects must either be immutable,
+ * or must also raise exceptions if any attempt to modify them is made. Of course, the object can return clones
+ * of internal objects, since those are safe. * @author davis
+ */
+public interface Freezable extends Cloneable {
+	/**
+	 * Determines whether the object has been locked or not.
+	 */
+	public boolean isFrozen();
+	/**
+	 * Locks the object.
+	 * @return the object itself.
+	 */
+	public Object freeze();
+	/**
+	 * Provides for the clone operation. Any clone is initially unlocked.
+	 */
+	public Object cloneAsThawed();
+}
\ No newline at end of file