diff --git a/lib/configuration.js b/lib/configuration.js
index 77f3969..8540ba5 100644
--- a/lib/configuration.js
+++ b/lib/configuration.js
@@ -99,6 +99,9 @@ const loaders = {
   '.cjs': loadScriptOrModule,
   '.mjs': loadScriptOrModule,
   '.js': loadScriptOrModule,
+  '.cts': loadScriptOrModule,
+  '.mts': loadScriptOrModule,
+  '.ts': loadScriptOrModule,
   '.yaml': loadYaml,
   '.yml': loadYaml
 }
diff --git a/readme.md b/readme.md
index e86a92f..ca01754 100644
--- a/readme.md
+++ b/readme.md
@@ -1223,7 +1223,11 @@ engine(
 
 This example processes `readme.md` and allows configuration from `.remarkrc`,
 `.remarkrc.json`, `.remarkrc.yml`, `.remarkrc.yaml`, `.remarkrc.js`,
-`.remarkrc.cjs`, and `.remarkrc.mjs` files.
+`.remarkrc.cjs`, `.remarkrc.mjs`, `.remarkrc.ts`, `.remarkrc.cts`, and
+`.remarkrc.mts` files.
+
+Note: TypeScript support relies on Node.js itself, so it requires Node.js 22.7+
+with `--experimental-transform-types` flag enabled or 23.6+ by default.
 
 ```js
 import {remark} from 'remark'
diff --git a/test/configuration-plugins.js b/test/configuration-plugins.js
index 41ef27b..13e7a85 100644
--- a/test/configuration-plugins.js
+++ b/test/configuration-plugins.js
@@ -1,5 +1,6 @@
 import assert from 'node:assert/strict'
 import path from 'node:path'
+import process from 'node:process'
 import test from 'node:test'
 import {engine} from 'unified-engine'
 import {cleanError} from './util/clean-error.js'
@@ -71,6 +72,50 @@ test('configuration (plugins)', async function (t) {
     }
   )
 
+  if (process.features.typescript) {
+    await t.test(
+      'should support an ESM plugin w/ an `.mts` extname',
+      async function () {
+        const stderr = spy()
+
+        globalThis.unifiedEngineTestCalls = 0
+
+        const result = await engine({
+          cwd: new URL('config-plugins-esm-mts/', fixtures),
+          files: ['one.txt'],
+          processor: noop(),
+          rcName: '.foorc',
+          streamError: stderr.stream
+        })
+
+        assert.equal(result.code, 0)
+        assert.equal(stderr(), 'one.txt: no issues found\n')
+        assert.equal(globalThis.unifiedEngineTestCalls, 1)
+      }
+    )
+
+    await t.test(
+      'should support an ESM plugin w/ a `.ts` extname',
+      async function () {
+        const stderr = spy()
+
+        globalThis.unifiedEngineTestCalls = 0
+
+        const result = await engine({
+          cwd: new URL('config-plugins-esm-ts/', fixtures),
+          files: ['one.txt'],
+          processor: noop(),
+          rcName: '.foorc',
+          streamError: stderr.stream
+        })
+
+        assert.equal(result.code, 0)
+        assert.equal(stderr(), 'one.txt: no issues found\n')
+        assert.equal(globalThis.unifiedEngineTestCalls, 1)
+      }
+    )
+  }
+
   await t.test('should handle failing plugins', async function () {
     const stderr = spy()
 
diff --git a/test/configuration.js b/test/configuration.js
index a1157e7..cb815ac 100644
--- a/test/configuration.js
+++ b/test/configuration.js
@@ -1,5 +1,6 @@
 import assert from 'node:assert/strict'
 import path from 'node:path'
+import process from 'node:process'
 import test from 'node:test'
 import {engine} from 'unified-engine'
 import {cleanError} from './util/clean-error.js'
@@ -202,6 +203,86 @@ test('configuration', async function (t) {
     )
   })
 
+  if (process.features.typescript) {
+    await t.test(
+      'should prefer `.rc.js` scripts over `.rc.ts`',
+      async function () {
+        const stderr = spy()
+        let calls = 0
+
+        const result = await engine({
+          cwd: new URL('mixed-rc-script/', fixtures),
+          extensions: ['txt'],
+          files: ['.'],
+          plugins: [
+            function () {
+              assert.deepEqual(this.data('settings'), {})
+              calls++
+            }
+          ],
+          processor: noop,
+          rcName: '.foorc',
+          streamError: stderr.stream
+        })
+
+        assert.deepEqual(
+          [result.code, calls, stderr()],
+          [0, 1, 'one.txt: no issues found\n']
+        )
+      }
+    )
+
+    await t.test('should support `.rc.mts` module', async function () {
+      const stderr = spy()
+      let calls = 0
+
+      const result = await engine({
+        cwd: new URL('rc-module-mts/', fixtures),
+        extensions: ['txt'],
+        files: ['.'],
+        plugins: [
+          function () {
+            assert.deepEqual(this.data('settings'), {foo: 'bar'})
+            calls++
+          }
+        ],
+        processor: noop,
+        rcName: '.foorc',
+        streamError: stderr.stream
+      })
+
+      assert.deepEqual(
+        [result.code, calls, stderr()],
+        [0, 1, 'one.txt: no issues found\n']
+      )
+    })
+
+    await t.test('should support `.rc.cts` module', async function () {
+      const stderr = spy()
+      let calls = 0
+
+      const result = await engine({
+        cwd: new URL('rc-module-cts/', fixtures),
+        extensions: ['txt'],
+        files: ['.'],
+        plugins: [
+          function () {
+            assert.deepEqual(this.data('settings'), {foo: 'bar'})
+            calls++
+          }
+        ],
+        processor: noop,
+        rcName: '.foorc',
+        streamError: stderr.stream
+      })
+
+      assert.deepEqual(
+        [result.code, calls, stderr()],
+        [0, 1, 'one.txt: no issues found\n']
+      )
+    })
+  }
+
   await t.test('should support `.rc.yaml` config files', async function () {
     const stderr = spy()
 
diff --git a/test/fixtures/config-plugins-esm-mts/.foorc b/test/fixtures/config-plugins-esm-mts/.foorc
new file mode 100644
index 0000000..4f69d3d
--- /dev/null
+++ b/test/fixtures/config-plugins-esm-mts/.foorc
@@ -0,0 +1,3 @@
+{
+  "plugins": ["./test.mts"]
+}
diff --git a/test/fixtures/config-plugins-esm-mts/one.txt b/test/fixtures/config-plugins-esm-mts/one.txt
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/config-plugins-esm-mts/test.mts b/test/fixtures/config-plugins-esm-mts/test.mts
new file mode 100644
index 0000000..2df4845
--- /dev/null
+++ b/test/fixtures/config-plugins-esm-mts/test.mts
@@ -0,0 +1,6 @@
+import assert from 'node:assert/strict'
+
+export default function test() {
+  assert(typeof globalThis.unifiedEngineTestCalls === 'number')
+  globalThis.unifiedEngineTestCalls++
+}
diff --git a/test/fixtures/config-plugins-esm-ts/.foorc b/test/fixtures/config-plugins-esm-ts/.foorc
new file mode 100644
index 0000000..304ab64
--- /dev/null
+++ b/test/fixtures/config-plugins-esm-ts/.foorc
@@ -0,0 +1,3 @@
+{
+  "plugins": ["./test.ts"]
+}
diff --git a/test/fixtures/config-plugins-esm-ts/one.txt b/test/fixtures/config-plugins-esm-ts/one.txt
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/config-plugins-esm-ts/package.json b/test/fixtures/config-plugins-esm-ts/package.json
new file mode 100644
index 0000000..3dbc1ca
--- /dev/null
+++ b/test/fixtures/config-plugins-esm-ts/package.json
@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}
diff --git a/test/fixtures/config-plugins-esm-ts/test.ts b/test/fixtures/config-plugins-esm-ts/test.ts
new file mode 100644
index 0000000..2df4845
--- /dev/null
+++ b/test/fixtures/config-plugins-esm-ts/test.ts
@@ -0,0 +1,6 @@
+import assert from 'node:assert/strict'
+
+export default function test() {
+  assert(typeof globalThis.unifiedEngineTestCalls === 'number')
+  globalThis.unifiedEngineTestCalls++
+}
diff --git a/test/fixtures/mixed-rc-script/.foorc.js b/test/fixtures/mixed-rc-script/.foorc.js
new file mode 100644
index 0000000..212bb12
--- /dev/null
+++ b/test/fixtures/mixed-rc-script/.foorc.js
@@ -0,0 +1,8 @@
+/**
+ * @import {Preset} from 'unified-engine'
+ */
+
+/** @type {Preset} */
+const config = {settings: {}}
+
+export default config
diff --git a/test/fixtures/mixed-rc-script/.foorc.ts b/test/fixtures/mixed-rc-script/.foorc.ts
new file mode 100644
index 0000000..83f83fb
--- /dev/null
+++ b/test/fixtures/mixed-rc-script/.foorc.ts
@@ -0,0 +1,9 @@
+import type {Preset} from 'unified-engine'
+
+const config: Preset = {
+  settings: {
+    foo: 'bar'
+  }
+}
+
+export default config
diff --git a/test/fixtures/mixed-rc-script/one.txt b/test/fixtures/mixed-rc-script/one.txt
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/rc-module-cts/.foorc.cts b/test/fixtures/rc-module-cts/.foorc.cts
new file mode 100644
index 0000000..960a6b9
--- /dev/null
+++ b/test/fixtures/rc-module-cts/.foorc.cts
@@ -0,0 +1,5 @@
+import type {Settings} from 'unified'
+
+exports.settings = {
+  foo: 'bar'
+} satisfies Settings
diff --git a/test/fixtures/rc-module-cts/one.txt b/test/fixtures/rc-module-cts/one.txt
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/rc-module-mts/.foorc.mts b/test/fixtures/rc-module-mts/.foorc.mts
new file mode 100644
index 0000000..8d9019a
--- /dev/null
+++ b/test/fixtures/rc-module-mts/.foorc.mts
@@ -0,0 +1,15 @@
+import type {Preset} from 'unified-engine'
+
+declare module 'unified' {
+  interface Settings {
+    foo: string
+  }
+}
+
+const config: Preset = {
+  settings: {
+    foo: 'bar'
+  }
+}
+
+export default config
diff --git a/test/fixtures/rc-module-mts/one.txt b/test/fixtures/rc-module-mts/one.txt
new file mode 100644
index 0000000..e69de29