diff --git a/package.json b/package.json
index 79c46408..45c9fa3f 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,6 @@
     "@rollup/plugin-typescript": "^11.1.6",
     "@types/expect": "^24.3.0",
     "@types/lodash": "^4.14.144",
-    "@types/mocha": "^10.0.0",
     "@types/node": "^18.7.14",
     "@typescript-eslint/eslint-plugin": "^7.1.1",
     "@typescript-eslint/parser": "^7.1.1",
@@ -39,11 +38,11 @@
     "is-url": "^1.2.4",
     "is-uuid": "^1.0.2",
     "lodash": "^4.17.15",
-    "mocha": "^10.0.0",
     "np": "^10.0.0",
     "prettier": "^3.2.5",
     "rollup": "^4.12.1",
-    "typescript": "^4.8.3"
+    "typescript": "^4.8.3",
+    "vitest": "^1.6.0"
   },
   "scripts": {
     "build": "rm -rf ./{dist} && rollup --config ./rollup.config.js",
@@ -55,9 +54,9 @@
     "lint:eslint": "eslint '{src,test}/*.{js,ts}'",
     "lint:prettier": "prettier --list-different '**/*.{js,json,ts}'",
     "release": "npm run build && npm run lint && np",
-    "test": "npm run build && npm run test:types && npm run test:mocha",
-    "test:mocha": "mocha --require ./test/register.cjs --require source-map-support/register ./test/index.ts",
+    "test": "npm run build && npm run test:types && npm run test:vitest",
     "test:types": "tsc --noEmit && tsc --project ./test/tsconfig.json --noEmit",
+    "test:vitest": "vitest run",
     "watch": "npm run build -- --watch"
   },
   "keywords": [
diff --git a/test/api/assert.ts b/test/api/assert.test.ts
similarity index 95%
rename from test/api/assert.ts
rename to test/api/assert.test.ts
index 65d55a56..a0479982 100644
--- a/test/api/assert.ts
+++ b/test/api/assert.test.ts
@@ -1,4 +1,5 @@
 import { throws, doesNotThrow } from 'assert'
+import { describe, it } from 'vitest'
 import { assert, string, StructError } from '../../src'
 
 describe('assert', () => {
diff --git a/test/api/create.ts b/test/api/create.test.ts
similarity index 97%
rename from test/api/create.ts
rename to test/api/create.test.ts
index 873d30ec..5f88db94 100644
--- a/test/api/create.ts
+++ b/test/api/create.test.ts
@@ -1,4 +1,5 @@
 import { strictEqual, deepEqual, deepStrictEqual, throws } from 'assert'
+import { describe, it } from 'vitest'
 import {
   type,
   optional,
diff --git a/test/api/is.ts b/test/api/is.test.ts
similarity index 91%
rename from test/api/is.ts
rename to test/api/is.test.ts
index 46789f95..8341a011 100644
--- a/test/api/is.ts
+++ b/test/api/is.test.ts
@@ -1,4 +1,5 @@
 import { strictEqual } from 'assert'
+import { describe, it } from 'vitest'
 import { is, string } from '../../src'
 
 describe('is', () => {
diff --git a/test/api/mask.ts b/test/api/mask.test.ts
similarity index 98%
rename from test/api/mask.ts
rename to test/api/mask.test.ts
index c054d978..7d360365 100644
--- a/test/api/mask.ts
+++ b/test/api/mask.test.ts
@@ -1,4 +1,5 @@
 import { deepStrictEqual, throws } from 'assert'
+import { describe, it } from 'vitest'
 import {
   mask,
   object,
diff --git a/test/api/validate.ts b/test/api/validate.test.ts
similarity index 98%
rename from test/api/validate.ts
rename to test/api/validate.test.ts
index cb6d878f..b87dda5f 100644
--- a/test/api/validate.ts
+++ b/test/api/validate.test.ts
@@ -1,4 +1,5 @@
 import { deepStrictEqual, strictEqual } from 'assert'
+import { describe, it } from 'vitest'
 import {
   validate,
   string,
diff --git a/test/index.test.ts b/test/index.test.ts
new file mode 100644
index 00000000..f61b9013
--- /dev/null
+++ b/test/index.test.ts
@@ -0,0 +1,116 @@
+import assert, { CallTracker } from 'assert'
+import fs from 'fs'
+import { pick } from 'lodash'
+import { basename, extname, resolve } from 'path'
+import { describe, it } from 'vitest'
+import {
+  any,
+  assert as assertValue,
+  Context,
+  create as createValue,
+  deprecated,
+  StructError,
+} from '../src'
+
+describe('superstruct', () => {
+  describe('validation', () => {
+    const kindsDir = resolve(__dirname, 'validation')
+    const kinds = fs
+      .readdirSync(kindsDir)
+      .filter((t) => t[0] !== '.')
+      .map((t) => basename(t, extname(t)))
+
+    for (const kind of kinds) {
+      describe(kind, async () => {
+        const testsDir = resolve(kindsDir, kind)
+        const tests = fs
+          .readdirSync(testsDir)
+          .filter((t) => t[0] !== '.')
+          .map((t) => basename(t, extname(t)))
+
+        for (const name of tests) {
+          const module = await import(resolve(testsDir, name))
+          const { Struct, data, create, only, skip, output, failures } = module
+          const run = only ? it.only : skip ? it.skip : it
+          run(name, () => {
+            let actual
+            let err
+
+            try {
+              if (create) {
+                actual = createValue(data, Struct)
+              } else {
+                assertValue(data, Struct)
+                actual = data
+              }
+            } catch (e) {
+              if (!(e instanceof StructError)) {
+                throw e
+              }
+
+              err = e
+            }
+
+            if ('output' in module) {
+              if (err) {
+                throw new Error(
+                  `Expected "${name}" fixture not to throw an error but it did:\n\n${err}`
+                )
+              }
+
+              assert.deepStrictEqual(actual, output)
+            } else if ('failures' in module) {
+              if (!err) {
+                throw new Error(
+                  `Expected "${name}" fixture to throw an error but it did not.`
+                )
+              }
+
+              const props = ['type', 'path', 'refinement', 'value', 'branch']
+              const actualFailures = err
+                .failures()
+                .map((failure) => pick(failure, ...props))
+
+              assert.deepStrictEqual(actualFailures, failures)
+              assert.deepStrictEqual(pick(err, ...props), failures[0])
+            } else {
+              throw new Error(
+                `The "${name}" fixture did not define an \`output\` or \`failures\` export.`
+              )
+            }
+          })
+        }
+      })
+    }
+  })
+
+  describe('deprecated', () => {
+    it('does not log deprecated type if value is undefined', () => {
+      const tracker = new CallTracker()
+      const logSpy = buildSpyWithZeroCalls(tracker)
+      assertValue(undefined, deprecated(any(), logSpy))
+      tracker.verify()
+    })
+
+    it('logs deprecated type to passed function if value is present', () => {
+      const tracker = new CallTracker()
+      const fakeLog = (value: unknown, ctx: Context) => {}
+      const logSpy = tracker.calls(fakeLog, 1)
+      assertValue('present', deprecated(any(), logSpy))
+      tracker.verify()
+    })
+  })
+})
+
+/**
+ * This emulates `tracker.calls(0)`.
+ *
+ * `CallTracker.calls` doesn't support passing `0`, therefore we expect it
+ * to be called once which is our call in this test. This proves that
+ * the following action didn't call it.
+ */
+function buildSpyWithZeroCalls(tracker: CallTracker) {
+  const logSpy = tracker.calls(1)
+  logSpy()
+  return logSpy
+}
diff --git a/test/index.ts b/test/index.ts
index 2d4bc819..d28f0685 100644
--- a/test/index.ts
+++ b/test/index.ts
@@ -1,129 +1,5 @@
-import assert, { CallTracker } from 'assert'
-import fs from 'fs'
-import { pick } from 'lodash'
-import { basename, extname, resolve } from 'path'
-import {
-  any,
-  assert as assertValue,
-  Context,
-  create as createValue,
-  deprecated,
-  StructError,
-} from '../src'
-
-describe('superstruct', () => {
-  describe('api', () => {
-    require('./api/assert')
-    require('./api/create')
-    require('./api/is')
-    require('./api/mask')
-    require('./api/validate')
-  })
-
-  describe('validation', () => {
-    const kindsDir = resolve(__dirname, 'validation')
-    const kinds = fs
-      .readdirSync(kindsDir)
-      .filter((t) => t[0] !== '.')
-      .map((t) => basename(t, extname(t)))
-
-    for (const kind of kinds) {
-      describe(kind, () => {
-        const testsDir = resolve(kindsDir, kind)
-        const tests = fs
-          .readdirSync(testsDir)
-          .filter((t) => t[0] !== '.')
-          .map((t) => basename(t, extname(t)))
-
-        for (const name of tests) {
-          const module = require(resolve(testsDir, name))
-          const { Struct, data, create, only, skip, output, failures } = module
-          const run = only ? it.only : skip ? it.skip : it
-          run(name, () => {
-            let actual
-            let err
-
-            try {
-              if (create) {
-                actual = createValue(data, Struct)
-              } else {
-                assertValue(data, Struct)
-                actual = data
-              }
-            } catch (e) {
-              if (!(e instanceof StructError)) {
-                throw e
-              }
-
-              err = e
-            }
-
-            if ('output' in module) {
-              if (err) {
-                throw new Error(
-                  `Expected "${name}" fixture not to throw an error but it did:\n\n${err}`
-                )
-              }
-
-              assert.deepStrictEqual(actual, output)
-            } else if ('failures' in module) {
-              if (!err) {
-                throw new Error(
-                  `Expected "${name}" fixture to throw an error but it did not.`
-                )
-              }
-
-              const props = ['type', 'path', 'refinement', 'value', 'branch']
-              const actualFailures = err
-                .failures()
-                .map((failure) => pick(failure, ...props))
-
-              assert.deepStrictEqual(actualFailures, failures)
-              assert.deepStrictEqual(pick(err, ...props), failures[0])
-            } else {
-              throw new Error(
-                `The "${name}" fixture did not define an \`output\` or \`failures\` export.`
-              )
-            }
-          })
-        }
-      })
-    }
-  })
-
-  describe('deprecated', () => {
-    it('does not log deprecated type if value is undefined', () => {
-      const tracker = new CallTracker()
-      const logSpy = buildSpyWithZeroCalls(tracker)
-      assertValue(undefined, deprecated(any(), logSpy))
-      tracker.verify()
-    })
-
-    it('logs deprecated type to passed function if value is present', () => {
-      const tracker = new CallTracker()
-      const fakeLog = (value: unknown, ctx: Context) => {}
-      const logSpy = tracker.calls(fakeLog, 1)
-      assertValue('present', deprecated(any(), logSpy))
-      tracker.verify()
-    })
-  })
-})
-
 /**
  * A helper for testing type signatures.
  */
 
 export function test<T>(fn: (x: unknown) => T) {}
-
-/**
- * This emulates `tracker.calls(0)`.
- *
- * `CallTracker.calls` doesn't support passing `0`, therefore we expect it
- * to be called once which is our call in this test. This proves that
- * the following action didn't call it.
- */
-function buildSpyWithZeroCalls(tracker: CallTracker) {
-  const logSpy = tracker.calls(1)
-  logSpy()
-  return logSpy
-}
diff --git a/test/tsconfig.json b/test/tsconfig.json
index 5197ce27..25d841e7 100644
--- a/test/tsconfig.json
+++ b/test/tsconfig.json
@@ -1,4 +1,7 @@
 {
   "extends": "../tsconfig.json",
-  "include": ["./**/*.ts"]
+  "include": ["./**/*.ts"],
+  "compilerOptions": {
+    "skipLibCheck": true
+  }
 }