diff --git a/.gitignore b/.gitignore
index bf4fb70..547aa64 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 node_modules
 build
 yarn.lock
+test-d/build.ts
diff --git a/rollup.config.js b/rollup.config.js
index db0976e..534a397 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -1,3 +1,4 @@
+import fs from 'node:fs/promises';
 import {nodeResolve} from '@rollup/plugin-node-resolve';
 import commonjs from '@rollup/plugin-commonjs';
 import json from '@rollup/plugin-json';
@@ -16,10 +17,11 @@ const stripComments = createTag(
 	replaceResultTransformer(emptyLineRegex, ''),
 );
 
+const sourceDirectory = 'source';
 const outputDirectory = 'build';
 
 const config = defineConfig({
-	input: await globby('source/**/*.js'),
+	input: await globby(`${sourceDirectory}/**/*.js`),
 	output: {
 		dir: outputDirectory,
 		interop: 'esModule',
@@ -58,7 +60,7 @@ const config = defineConfig({
 });
 
 const dtsConfig = defineConfig({
-	input: './source/index.d.ts',
+	input: `./${sourceDirectory}/index.d.ts`,
 	output: {
 		file: `./${outputDirectory}/index.d.ts`,
 		format: 'es',
@@ -67,6 +69,18 @@ const dtsConfig = defineConfig({
 		dts({
 			respectExternal: true,
 		}),
+		{
+			name: 'copy-tsd',
+			async generateBundle() {
+				let tsdFile = await fs.readFile('./test-d/index.ts', 'utf8');
+				tsdFile = tsdFile.replace(
+					`import meow from '../${sourceDirectory}/index.js'`,
+					`import meow from '../${outputDirectory}/index.js'`,
+				);
+
+				await fs.writeFile(`./test-d/${outputDirectory}.ts`, tsdFile);
+			},
+		},
 	],
 });
 
diff --git a/test-d/build.test-d.ts b/test-d/build.test-d.ts
deleted file mode 100644
index 532e7e2..0000000
--- a/test-d/build.test-d.ts
+++ /dev/null
@@ -1,131 +0,0 @@
-import {expectAssignable, expectError, expectType} from 'tsd';
-import type {PackageJson} from 'type-fest';
-import meow, {type Result} from '../build/index.js';
-
-type AnyFlag = NonNullable<NonNullable<Parameters<typeof meow>[0]>['flags']>[string];
-
-const importMeta = import.meta;
-
-expectError(meow('Help text'));
-expectError(meow('Help text', {}));
-expectType<Result<never>>(meow('Help text', {importMeta}));
-expectAssignable<{flags: {foo: number}}>(
-	meow({importMeta: import.meta, flags: {foo: {type: 'number', isRequired: true}}}),
-);
-expectAssignable<{flags: {foo: string}}>(
-	meow({importMeta, flags: {foo: {type: 'string', isRequired: true}}}),
-);
-expectAssignable<{flags: {foo: boolean}}>(
-	meow({importMeta, flags: {foo: {type: 'boolean', isRequired: true}}}),
-);
-expectAssignable<{flags: {foo: number | undefined}}>(
-	meow({importMeta, flags: {foo: {type: 'number'}}}),
-);
-expectAssignable<{flags: {foo: string | undefined}}>(
-	meow({importMeta, flags: {foo: {type: 'string'}}}),
-);
-expectAssignable<{flags: {foo: boolean | undefined}}>(
-	meow({importMeta, flags: {foo: {type: 'boolean'}}}),
-);
-expectAssignable<{flags: {foo: number[] | undefined}}>(
-	meow({importMeta, flags: {foo: {type: 'number', isMultiple: true}}}),
-);
-expectAssignable<{flags: {foo: string[] | undefined}}>(
-	meow({importMeta, flags: {foo: {type: 'string', isMultiple: true}}}),
-);
-expectAssignable<{flags: {foo: boolean[] | undefined}}>(
-	meow({importMeta, flags: {foo: {type: 'boolean', isMultiple: true}}}),
-);
-expectType<Result<never>>(meow({importMeta, description: 'foo'}));
-expectType<Result<never>>(meow({importMeta, description: false}));
-expectType<Result<never>>(meow({importMeta, help: 'foo'}));
-expectType<Result<never>>(meow({importMeta, help: false}));
-expectType<Result<never>>(meow({importMeta, version: 'foo'}));
-expectType<Result<never>>(meow({importMeta, autoHelp: false}));
-expectType<Result<never>>(meow({importMeta, autoVersion: false}));
-expectType<Result<never>>(meow({importMeta, pkg: {foo: 'bar'}}));
-expectType<Result<never>>(meow({importMeta, argv: ['foo', 'bar']}));
-expectType<Result<never>>(meow({importMeta, inferType: true}));
-expectType<Result<never>>(meow({importMeta, booleanDefault: true}));
-expectType<Result<never>>(meow({importMeta, booleanDefault: undefined}));
-expectType<Result<never>>(meow({importMeta}));
-
-const result = meow('Help text', {
-	importMeta,
-	flags: {
-		foo: {type: 'boolean', shortFlag: 'f'},
-		'foo-bar': {type: 'number', aliases: ['foobar', 'fooBar']},
-		bar: {type: 'string', default: ''},
-		abc: {type: 'string', isMultiple: true},
-		baz: {type: 'string', choices: ['rainbow', 'cat', 'unicorn']},
-	},
-});
-
-expectType<string[]>(result.input);
-expectType<PackageJson>(result.pkg);
-expectType<string>(result.help);
-
-expectType<boolean | undefined>(result.flags.foo);
-expectType<number | undefined>(result.flags.fooBar);
-expectType<string>(result.flags.bar);
-expectType<string[] | undefined>(result.flags.abc);
-expectType<string | undefined>(result.flags.baz);
-expectType<boolean | undefined>(result.unnormalizedFlags.foo);
-expectType<unknown>(result.unnormalizedFlags.f);
-expectType<number | undefined>(result.unnormalizedFlags['foo-bar']);
-expectType<unknown>(result.unnormalizedFlags.foobar);
-expectType<unknown>(result.unnormalizedFlags.fooBar);
-expectType<string>(result.unnormalizedFlags.bar);
-expectType<string[] | undefined>(result.unnormalizedFlags.abc);
-expectType<string | undefined>(result.unnormalizedFlags.baz);
-
-result.showHelp();
-result.showHelp(1);
-result.showVersion();
-
-const options = {
-	importMeta,
-	flags: {
-		rainbow: {
-			type: 'boolean',
-			shortFlag: 'r',
-		},
-	},
-} as const;
-
-meow('', options);
-
-expectAssignable<AnyFlag>({type: 'string', default: 'cat'});
-expectAssignable<AnyFlag>({type: 'number', default: 42});
-expectAssignable<AnyFlag>({type: 'boolean', default: true});
-
-expectAssignable<AnyFlag>({type: 'string', default: undefined});
-expectAssignable<AnyFlag>({type: 'number', default: undefined});
-expectAssignable<AnyFlag>({type: 'boolean', default: undefined});
-
-expectAssignable<AnyFlag>({type: 'string', isMultiple: true, default: ['cat']});
-expectAssignable<AnyFlag>({type: 'number', isMultiple: true, default: [42]});
-expectAssignable<AnyFlag>({type: 'boolean', isMultiple: true, default: [false]});
-
-expectError<AnyFlag>({type: 'string', isMultiple: true, default: 'cat'});
-expectError<AnyFlag>({type: 'number', isMultiple: true, default: 42});
-expectError<AnyFlag>({type: 'boolean', isMultiple: true, default: false});
-
-expectAssignable<AnyFlag>({type: 'string', choices: ['cat', 'unicorn']});
-expectAssignable<AnyFlag>({type: 'number', choices: [1, 2]});
-expectAssignable<AnyFlag>({type: 'boolean', choices: [true, false]});
-expectAssignable<AnyFlag>({type: 'string', isMultiple: true, choices: ['cat']});
-expectAssignable<AnyFlag>({type: 'string', isMultiple: false, choices: ['cat']});
-
-expectError<AnyFlag>({type: 'string', choices: 'cat'});
-expectError<AnyFlag>({type: 'number', choices: 1});
-expectError<AnyFlag>({type: 'boolean', choices: true});
-
-expectError<AnyFlag>({type: 'string', choices: [1]});
-expectError<AnyFlag>({type: 'number', choices: ['cat']});
-expectError<AnyFlag>({type: 'boolean', choices: ['cat']});
-
-expectAssignable<AnyFlag>({choices: ['cat']});
-expectAssignable<AnyFlag>({choices: [1]});
-expectAssignable<AnyFlag>({choices: [true]});
-expectError<AnyFlag>({choices: ['cat', 1, true]});
diff --git a/test-d/index.test-d.ts b/test-d/index.ts
similarity index 100%
rename from test-d/index.test-d.ts
rename to test-d/index.ts