diff --git a/CountItems/CountWorker.js b/CountItems/CountWorker.js
index f60da543..7887ea29 100644
--- a/CountItems/CountWorker.js
+++ b/CountItems/CountWorker.js
@@ -5,6 +5,7 @@ const monitoring = require('../utils/monitoring');
 const { deserializeBigInts, serializeBigInts } = require('./utils/utils');
 
 const PENSIEVE = 'PENSIEVE';
+
 class CountWorker {
     constructor(params) {
         this.log = params.log;
@@ -66,12 +67,16 @@ class CountWorker {
         if (!this.client.client) {
             return callback(new Error('NotConnected'));
         }
-        // 'fromObj' expects that the website configuration is an instance of
-        // WebsiteConfiguration as it is not used in CountItems, we nullify it.
-        if (bucketInfoObj._websiteConfiguration) {
-            Object.assign(bucketInfoObj, { _websiteConfiguration: null });
+        const bucketInfoData = bucketInfoObj.bucketInfo || bucketInfoObj;
+        // 'fromObj' expects class-backed fields to already be instances.
+        // They are not used in CountItems, so we nullify unsupported serialized fields.
+        if (bucketInfoData._websiteConfiguration) {
+            bucketInfoData._websiteConfiguration = null;
+        }
+        if (bucketInfoData._bucketLoggingStatus) {
+            bucketInfoData._bucketLoggingStatus = null;
         }
-        const bucketInfo = BucketInfo.fromObj(bucketInfoObj.bucketInfo || bucketInfoObj);
+        const bucketInfo = BucketInfo.fromObj(bucketInfoData);
         const bucketName = bucketInfo.getName();
         this.log.info(`${process.pid} handling ${bucketName}`);
         return async.waterfall([
diff --git a/package.json b/package.json
index 886bb11a..d1791434 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "s3utils",
-  "version": "1.17.11",
+  "version": "1.17.12",
   "engines": {
     "node": ">= 22"
   },
diff --git a/tests/unit/CountItems/CountWorker.js b/tests/unit/CountItems/CountWorker.js
index 846df3e0..f28a8b9b 100644
--- a/tests/unit/CountItems/CountWorker.js
+++ b/tests/unit/CountItems/CountWorker.js
@@ -223,6 +223,42 @@ describe('CountItems::CountWorker', () => {
         });
     });
 
+    test('should nullify unsupported serialized bucket info fields', done => {
+        const testSendFn = jest.fn();
+        const w = new CountWorker({
+            log: new DummyLogger(),
+            sendFn: testSendFn,
+            client: mongoMock,
+        });
+        const bucketInfo = {
+            _name: 'test-bucket',
+            _owner: 'any',
+            _ownerDisplayName: 'any',
+            _creationDate: Date.now().toString(),
+            _websiteConfiguration: {
+                _indexDocument: 'index.html',
+            },
+            _bucketLoggingStatus: {
+                _loggingEnabled: {
+                    TargetBucket: 'target-bucket',
+                    TargetPrefix: 'logs/',
+                },
+            },
+        };
+        w.getIsTransient = jest.fn((bucketInfo, cb) => cb(null, true));
+        mongoMock.setup.mockImplementationOnce(cb => cb());
+        mongoMock.close.mockImplementationOnce(cb => cb());
+        mongoMock.client.isConnected.mockImplementationOnce(() => false);
+        mongoMock.getObjectMDStats.mockImplementationOnce((_a, _b, _c, _d, cb) => cb(null, { value: 42 }));
+        w.countItems(bucketInfo, (err, results) => {
+            expect(err).toBeNull();
+            expect(results).toEqual({ value: 42 });
+            expect(bucketInfo._websiteConfiguration).toBeNull();
+            expect(bucketInfo._bucketLoggingStatus).toBeNull();
+            done();
+        });
+    });
+
     describe('CountWorker.getIsTransient method', () => {
         let worker;
         let mockBucketInfo;