diff --git a/docs/api-reference.md b/docs/api-reference.md
index f2b90803..9738396e 100644
--- a/docs/api-reference.md
+++ b/docs/api-reference.md
@@ -382,6 +382,14 @@ function myWrappedTwMerge(...args: ClassNameValue[]) {
 }
 ```
 
+## `ClassValidator`
+
+```ts
+type ClassValidator = (value: string) => boolean
+```
+
+TypeScript type for class validators accepted in class definitions within [`extendTailwindMerge`](#extendtailwindmerge) and [`createTailwindMerge`](#createtailwindmerge).
+
 ---
 
 Next: [Writing plugins](./writing-plugins.md)
diff --git a/src/index.ts b/src/index.ts
index 1e043fe6..25d16cb2 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -5,5 +5,10 @@ export { fromTheme } from './lib/from-theme'
 export { mergeConfigs } from './lib/merge-configs'
 export { twJoin, type ClassNameValue } from './lib/tw-join'
 export { twMerge } from './lib/tw-merge'
-export { type Config, type DefaultClassGroupIds, type DefaultThemeGroupIds } from './lib/types'
+export {
+    type ClassValidator,
+    type Config,
+    type DefaultClassGroupIds,
+    type DefaultThemeGroupIds,
+} from './lib/types'
 export * as validators from './lib/validators'
diff --git a/tests/public-api.test.ts b/tests/public-api.test.ts
index 12deb896..2fa33cad 100644
--- a/tests/public-api.test.ts
+++ b/tests/public-api.test.ts
@@ -1,5 +1,6 @@
 import {
     ClassNameValue,
+    ClassValidator,
     Config,
     DefaultClassGroupIds,
     DefaultThemeGroupIds,
@@ -40,12 +41,14 @@ test('has correct export types', () => {
     const noRun = () => {
         const config: Config<DefaultClassGroupIds, DefaultThemeGroupIds> = getDefaultConfig()
         const classNameValue: ClassNameValue = 'some-class'
+        const classValidator: ClassValidator = (value: string) => false
 
         twMerge(classNameValue, classNameValue, classNameValue)
         twJoin(classNameValue, classNameValue, classNameValue)
 
         return {
             config,
+            classValidator,
         }
     }
 })