diff --git a/docs/api-reference/uiSchema.md b/docs/api-reference/uiSchema.md
index 1f8d567ce8..2575191ce4 100644
--- a/docs/api-reference/uiSchema.md
+++ b/docs/api-reference/uiSchema.md
@@ -90,7 +90,7 @@ See [Custom Widgets and Fields](https://react-jsonschema-form.readthedocs.io/en/
 
 ### classNames
 
-The uiSchema object accepts a `classNames` property for each field of the schema:
+The uiSchema object accepts a `ui:classNames` property for each field of the schema:
 
 ```tsx
 import { UiSchema } from "@rjsf/utils";
diff --git a/docs/quickstart.md b/docs/quickstart.md
index 0f03d62e80..cb32ccaec9 100644
--- a/docs/quickstart.md
+++ b/docs/quickstart.md
@@ -63,7 +63,7 @@ const schema: RJSFSchema = {
 };
 
 const uiSchema: UiSchema = {
-  classNames: "custom-css-class"
+  "ui:classNames": "custom-css-class"
 };
 
 render((
@@ -94,10 +94,10 @@ const schema: RJSFSchema = {
 
 const uiSchema: UiSchema = {
   name: {
-    classNames: "custom-class-name"
+    "ui:classNames": "custom-class-name"
   },
   age: {
-    classNames: "custom-class-age"
+    "ui:classNames": "custom-class-age"
   }
 }