diff --git a/CHANGELOG.md b/CHANGELOG.md
index c44f8a9..b7675a9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Release Notes for CKEditor for Craft CMS
 
+## Unreleased
+
+- Fixed a bug where custom `toolbar` config settings were getting ignored. ([#522](https://github.com/craftcms/ckeditor/issues/522))
+
 ## 5.1.0 - 2026-03-05
 
 - Updated CKEditor 5 to 47.6.0. ([#518](https://github.com/craftcms/ckeditor/pull/518))
diff --git a/src/Field.php b/src/Field.php
index a059ed5..b1b7a98 100644
--- a/src/Field.php
+++ b/src/Field.php
@@ -1446,13 +1446,15 @@ private function _inputHtml(mixed $value, ?ElementInterface $element, bool $stat
     language: $languageJs,
   }, $baseConfigJs, $configOptionsJs, {
     plugins: $configPlugins,
-    toolbar: {
-      items: $toolbarJs
-    },
     removePlugins: []
   });
 
 
+  if (!jQuery.isPlainObject(config.toolbar)) {
+    config.toolbar = {};
+  }
+  config.toolbar.items = $toolbarJs;
+
   // special case for heading config, because of the Heading Levels
   // see https://github.com/craftcms/ckeditor/issues/431
   const baseHeadings = $baseConfigJs?.heading?.options;