diff --git a/modules/data/spec/reducers/entity-change-tracker-base.spec.ts b/modules/data/spec/reducers/entity-change-tracker-base.spec.ts
index 4b85dbd5a4..8ba2c7bd5e 100644
--- a/modules/data/spec/reducers/entity-change-tracker-base.spec.ts
+++ b/modules/data/spec/reducers/entity-change-tracker-base.spec.ts
@@ -580,6 +580,22 @@ describe('EntityChangeTrackerBase', () => {
       const collection = tracker.trackDeleteMany(['1234', 456], origCollection);
       expect(collection).toBe(origCollection);
     });
+
+    it('should not mutate changeState when called on a tracked "updated" entity', () => {
+      const existingEntity = getFirstExistingEntity();
+      const updatedEntity = toUpdate({
+        ...existingEntity,
+        name: 'test update',
+      });
+      const collection = tracker.trackUpdateOne(updatedEntity, origCollection);
+      const change = collection.changeState[existingEntity!.id];
+      expect(change).toBeDefined();
+      expectChangeType(change, ChangeType.Updated);
+      Object.freeze(change);
+      expect(() => {
+        tracker.trackDeleteMany([existingEntity!.id], collection);
+      }).not.toThrowError();
+    });
   });
 
   describe('#trackUpdateOne', () => {
diff --git a/modules/data/src/reducers/entity-change-tracker-base.ts b/modules/data/src/reducers/entity-change-tracker-base.ts
index b748f1d267..40ac0c0399 100644
--- a/modules/data/src/reducers/entity-change-tracker-base.ts
+++ b/modules/data/src/reducers/entity-change-tracker-base.ts
@@ -454,7 +454,7 @@ export class EntityChangeTrackerBase<T> implements EntityChangeTracker<T> {
           } else if (trackedChange.changeType === ChangeType.Updated) {
             // Special case: switch change type from Updated to Deleted.
             cloneChgStateOnce();
-            trackedChange.changeType = ChangeType.Deleted;
+            chgState[id] = { ...chgState[id], changeType: ChangeType.Deleted };
           }
         } else {
           // Start tracking this entity