diff --git a/lib/index.js b/lib/index.js
index e6e255e..31f13f5 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -5,7 +5,14 @@
  */
 
 /**
- * @callback Dictionary
+ * @typedef Dictionary
+ *   A hunspell dictionary.
+ * @property {Uint8Array} aff
+ *   Data for the affix file (defines the language, keyboard, flags, and more).
+ * @property {Uint8Array} dic
+ *   Data for the dictionary file (contains words and flags applying to those words).
+ *
+ * @callback DictionaryCallback
  *   Dictionary function.
  * @param {DictionaryOnLoad} onload
  *   Callback called when the dictionary is loaded.
@@ -18,7 +25,7 @@
  *   Callback called when the dictionary is loaded.
  * @param {Error | undefined} error
  *   Error.
- * @param {unknown} [result]
+ * @param {Dictionary} [result]
  *   Dictionary.
  * @returns {undefined | void}
  *   Nothing.
@@ -27,8 +34,8 @@
  *
  * @typedef Options
  *   Configuration.
- * @property {Dictionary} dictionary
- *   Dictionary function (required);
+ * @property {Dictionary | DictionaryCallback} dictionary
+ *   Dictionary (required);
  *   result of importing one of the dictionaries in `wooorm/dictionaries`.
  * @property {ReadonlyArray<string> | null | undefined} [ignore]
  *   List of words to ignore (optional).
@@ -80,15 +87,17 @@ const emptyIgnore = []
 /**
  * Check spelling.
  *
- * @param {Readonly<Options> | Dictionary} options
+ * @param {Readonly<Options> | DictionaryCallback | Dictionary} options
  *   Configuration or dictionary (required).
  * @returns
  *   Transform.
  */
 export default function retextSpell(options) {
   const settings =
-    typeof options === 'function' ? {dictionary: options} : options || {}
-  const dictionary = settings.dictionary
+    typeof options === 'function' ||
+    (options && 'aff' in options && 'dic' in options)
+      ? {dictionary: options}
+      : options || {}
   const ignore = settings.ignore || emptyIgnore
   const ignoreLiteral =
     typeof settings.ignoreLiteral === 'boolean' ? settings.ignoreLiteral : true
@@ -102,7 +111,7 @@ export default function retextSpell(options) {
       : true
   const personal = settings.personal
 
-  if (typeof dictionary !== 'function') {
+  if (!settings.dictionary) {
     throw new TypeError('Missing `dictionary` in options')
   }
 
@@ -125,7 +134,11 @@ export default function retextSpell(options) {
 
   // Callback called when a `dictionary` is loaded or when `load`ing failed.
   // Flushes the queue when available, and sets the results on the parent scope.
-  dictionary(onload)
+  if (typeof settings.dictionary === 'function') {
+    settings.dictionary(onload)
+  } else {
+    onload(undefined, settings.dictionary)
+  }
 
   /**
    * Transform.
diff --git a/package.json b/package.json
index efcf912..5cff3f3 100644
--- a/package.json
+++ b/package.json
@@ -50,6 +50,7 @@
     "@types/node": "^20.0.0",
     "c8": "^8.0.0",
     "dictionary-en": "^3.0.0",
+    "dictionary-en-v4": "npm:dictionary-en@^4.0.0",
     "prettier": "^3.0.0",
     "remark-cli": "^11.0.0",
     "remark-preset-wooorm": "^9.0.0",
diff --git a/test.js b/test.js
index fd62104..28f2bb0 100644
--- a/test.js
+++ b/test.js
@@ -1,6 +1,7 @@
 import assert from 'node:assert/strict'
 import test from 'node:test'
 import dictionaryEn from 'dictionary-en'
+import dictionaryEnV4 from 'dictionary-en-v4'
 import {retext} from 'retext'
 import retextEmoji from 'retext-emoji'
 import retextSpell from 'retext-spell'
@@ -78,6 +79,16 @@ test('retextSpell', async function (t) {
     ])
   })
 
+  await t.test('should work with newer dictionary versions', async function () {
+    const file = await retext()
+      .use(retextSpell, dictionaryEnV4)
+      .process('kolor')
+
+    assert.deepEqual(file.messages.map(String), [
+      '1:1-1:6: Unexpected unknown word `kolor`, expected for example `color`, `dolor`'
+    ])
+  })
+
   await t.test('should work w/ repeated misspellings', async function () {
     const file = await retext()
       .use(retextSpell, dictionaryEn)