diff --git a/icu4j/main/classes/core/src/com/ibm/icu/util/MeasureUnit.java b/icu4j/main/classes/core/src/com/ibm/icu/util/MeasureUnit.java
index cdc8666..2bce398 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/util/MeasureUnit.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/util/MeasureUnit.java
@@ -704,7 +704,7 @@ public String toString() {
      *
      * @stable ICU 53
      */
-    public synchronized static Set<String> getAvailableTypes() {
+    public static Set<String> getAvailableTypes() {
         populateCache();
         return Collections.unmodifiableSet(cache.keySet());
     }
@@ -715,7 +715,7 @@ public synchronized static Set<String> getAvailableTypes() {
      * @return the available units for type. Returned set is unmodifiable.
      * @stable ICU 53
      */
-    public synchronized static Set<MeasureUnit> getAvailable(String type) {
+    public static Set<MeasureUnit> getAvailable(String type) {
         populateCache();
         Map<String, MeasureUnit> units = cache.get(type);
         // Train users not to modify returned set from the start giving us more
@@ -867,11 +867,9 @@ public void put(UResource.Key key, UResource.Value value, boolean noFallback) {
      * Adding of others is deferred until later to avoid circular static init
      * dependencies with classes Currency and TimeUnit.
      *
-     * <p>Synchronization: this function must be called from static synchronized methods only.
-     *
      * @internal
      */
-    static private void populateCache() {
+    static synchronized private void populateCache() {
         if (cacheIsPopulated) {
             return;
         }