diff --git a/CHANGELOG.md b/CHANGELOG.md
index a784ffb9..03d8ccf4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## 22.0-SNAPSHOT - unreleased
 
+### ⚙️ Technical
+* Improvements to serialization efficiency of replicated `Cache` and `CachedValue`
+
 ## 21.0.0 - 2024-09-03
 
 ### 💥 Breaking Changes (upgrade difficulty: 🟢 LOW - latest Hoist React + DB col additions)
diff --git a/src/main/groovy/io/xh/hoist/cache/BaseCache.groovy b/src/main/groovy/io/xh/hoist/cache/BaseCache.groovy
index be5e146c..faed7bcc 100644
--- a/src/main/groovy/io/xh/hoist/cache/BaseCache.groovy
+++ b/src/main/groovy/io/xh/hoist/cache/BaseCache.groovy
@@ -7,8 +7,7 @@
 
 package io.xh.hoist.cache
 
-import com.hazelcast.core.EntryEvent
-import com.hazelcast.core.EntryListener
+
 import groovy.transform.CompileStatic
 import io.xh.hoist.BaseService
 import io.xh.hoist.cluster.ClusterService
@@ -53,7 +52,7 @@ abstract class BaseCache<V> {
     public final boolean serializeOldValue
 
     /** Handlers to be called on change with a {@link CacheValueChanged} object. */
-    public final List<Closure> onChange
+    public final List<Closure> onChange = []
 
     BaseCache(
         BaseService svc,
@@ -62,8 +61,7 @@ abstract class BaseCache<V> {
         Closure expireFn,
         Closure timestampFn,
         boolean replicate,
-        boolean serializeOldValue,
-        Closure onChange
+        boolean serializeOldValue
     ) {
         this.svc = svc
         this.name = name
@@ -72,13 +70,10 @@ abstract class BaseCache<V> {
         this.timestampFn = timestampFn
         this.replicate = replicate
         this.serializeOldValue = serializeOldValue
-        this.onChange = onChange ? [onChange] : []
     }
 
     /** @param handler called on change with a {@link CacheValueChanged} object. */
-    void addChangeHandler(Closure handler) {
-        onChange << handler
-    }
+    abstract void addChangeHandler(Closure handler)
 
     /** Clear all values. */
     abstract void clear()
@@ -90,19 +85,6 @@ abstract class BaseCache<V> {
         return replicate && ClusterService.multiInstanceEnabled
     }
 
-    protected EntryListener getHzEntryListener() {
-        Closure onChg = { EntryEvent<?, Entry<V>> it ->
-            fireOnChange(it.key, it.oldValue?.value, it.value?.value)
-        }
-        return [
-            entryAdded  : onChg,
-            entryUpdated: onChg,
-            entryRemoved: onChg,
-            entryEvicted: onChg,
-            entryExpired: onChg
-        ] as EntryListener
-    }
-
     protected void fireOnChange(Object key, V oldValue, V value) {
         def change = new CacheValueChanged(this, key, oldValue,  value)
         onChange.each { it.call(change) }
diff --git a/src/main/groovy/io/xh/hoist/cache/Cache.groovy b/src/main/groovy/io/xh/hoist/cache/Cache.groovy
index bf758cdd..26aa17c3 100644
--- a/src/main/groovy/io/xh/hoist/cache/Cache.groovy
+++ b/src/main/groovy/io/xh/hoist/cache/Cache.groovy
@@ -41,18 +41,14 @@ class Cache<K,V> extends BaseCache<V> {
         @NamedParam boolean serializeOldValue = false,
         @NamedParam Closure onChange = null
     ) {
-        super(svc, name, expireTime, expireFn, timestampFn, replicate, serializeOldValue, onChange)
+        super(svc, name, expireTime, expireFn, timestampFn, replicate, serializeOldValue)
 
         if (replicate && !name) {
             throw new IllegalArgumentException("Cannot create a replicated Cache without a unique name")
         }
 
-        if (useCluster) {
-            _map = svc.getReplicatedMap(name)
-            (_map as ReplicatedMap).addEntryListener(getHzEntryListener())
-        } else {
-            _map = new ConcurrentHashMap()
-        }
+        _map = useCluster ? svc.getReplicatedMap(name) : new ConcurrentHashMap()
+        if (onChange) addChangeHandler(onChange)
 
         timer = new Timer(
             owner: svc,
@@ -131,6 +127,14 @@ class Cache<K,V> extends BaseCache<V> {
         _map.each { k, v -> remove(k)}
     }
 
+    void addChangeHandler(Closure handler) {
+        if (!onChange && _map instanceof ReplicatedMap) {
+            _map.addEntryListener(new HzEntryListener(this))
+        }
+        onChange << handler
+    }
+
+
     /**
      * Wait for the cache entry to be populated.
      * @param key, entry to check
diff --git a/src/main/groovy/io/xh/hoist/cache/CachedValue.groovy b/src/main/groovy/io/xh/hoist/cache/CachedValue.groovy
index a06e0fbe..91103548 100644
--- a/src/main/groovy/io/xh/hoist/cache/CachedValue.groovy
+++ b/src/main/groovy/io/xh/hoist/cache/CachedValue.groovy
@@ -10,8 +10,6 @@ import java.util.concurrent.TimeoutException
 import static io.xh.hoist.util.DateTimeUtils.SECONDS
 import static io.xh.hoist.util.DateTimeUtils.intervalElapsed
 import static java.lang.System.currentTimeMillis
-import static java.util.Collections.emptyMap
-
 
 /**
  * Similar to {@link Cache}, but a single value that can be read, written, and expired.
@@ -32,14 +30,10 @@ class CachedValue<V> extends BaseCache<V> {
         @NamedParam boolean serializeOldValue = false,
         @NamedParam Closure onChange = null
     ) {
-        super(svc, name, expireTime, expireFn, timestampFn, replicate, serializeOldValue, onChange)
+        super(svc, name, expireTime, expireFn, timestampFn, replicate, serializeOldValue)
 
-        if (useCluster) {
-            _map = svc.replicatedCachedValuesMap
-            (_map as ReplicatedMap).addEntryListener(getHzEntryListener(), name)
-        } else {
-            _map = svc.localCachedValuesMap
-        }
+        _map = useCluster ? svc.replicatedCachedValuesMap : svc.localCachedValuesMap
+        if (onChange) addChangeHandler(onChange)
     }
 
     /** @returns the cached value. */
@@ -108,4 +102,11 @@ class CachedValue<V> extends BaseCache<V> {
             throw new TimeoutException(msg)
         }
     }
+
+    void addChangeHandler(Closure handler) {
+        if (!onChange && _map instanceof ReplicatedMap) {
+            _map.addEntryListener(new HzEntryListener(this), name)
+        }
+        onChange << handler
+    }
 }
diff --git a/src/main/groovy/io/xh/hoist/cache/HzEntryListener.groovy b/src/main/groovy/io/xh/hoist/cache/HzEntryListener.groovy
new file mode 100644
index 00000000..59333c07
--- /dev/null
+++ b/src/main/groovy/io/xh/hoist/cache/HzEntryListener.groovy
@@ -0,0 +1,43 @@
+package io.xh.hoist.cache
+
+import com.hazelcast.core.EntryEvent
+import com.hazelcast.core.EntryListener
+import com.hazelcast.map.MapEvent
+
+class HzEntryListener implements EntryListener {
+
+    private BaseCache target
+
+    HzEntryListener(BaseCache target) {
+        this.target = target
+    }
+
+    void entryAdded(EntryEvent event) {
+        fireEvent(event)
+    }
+
+    void entryEvicted(EntryEvent event) {
+        fireEvent(event)
+    }
+
+    void entryExpired(EntryEvent event) {
+        fireEvent(event)
+    }
+
+    void entryRemoved(EntryEvent event) {
+        fireEvent(event)
+    }
+
+    void entryUpdated(EntryEvent event) {
+        fireEvent(event)
+    }
+
+    void mapCleared(MapEvent event) {}
+
+    void mapEvicted(MapEvent event) {}
+
+    private fireEvent(EntryEvent event) {
+        target.fireOnChange(event.key, event.oldValue?.value, event.value?.value)
+    }
+
+}