diff --git a/package.json b/package.json
index c48b45b3..dd7ac87f 100644
--- a/package.json
+++ b/package.json
@@ -57,7 +57,6 @@
 		"npm-name": "^8.0.0",
 		"onetime": "^7.0.0",
 		"open": "^10.0.4",
-		"ow": "^1.1.1",
 		"p-memoize": "^7.1.1",
 		"p-timeout": "^6.1.2",
 		"path-exists": "^5.0.0",
diff --git a/source/npm/util.js b/source/npm/util.js
index e72177e2..c1a6e2c5 100644
--- a/source/npm/util.js
+++ b/source/npm/util.js
@@ -2,7 +2,6 @@ import path from 'node:path';
 import {pathExists} from 'path-exists';
 import {execa} from 'execa';
 import pTimeout from 'p-timeout';
-import ow from 'ow';
 import npmName from 'npm-name';
 import chalk from 'chalk-template';
 import * as util from '../util.js';
@@ -48,7 +47,7 @@ export const isExternalRegistry = package_ => typeof package_.publishConfig?.reg
 
 export const collaborators = async package_ => {
 	const packageName = package_.name;
-	ow(packageName, ow.string);
+	util.assert(typeof packageName === 'string', 'Package name is required');
 
 	const arguments_ = ['access', 'list', 'collaborators', packageName, '--json'];
 
@@ -70,7 +69,7 @@ export const collaborators = async package_ => {
 };
 
 export const prereleaseTags = async packageName => {
-	ow(packageName, ow.string);
+	util.assert(typeof packageName === 'string', 'Package name is required');
 
 	let tags = [];
 	try {
diff --git a/source/util.js b/source/util.js
index e19cc7c7..229d6b10 100644
--- a/source/util.js
+++ b/source/util.js
@@ -7,12 +7,17 @@ import issueRegex from 'issue-regex';
 import terminalLink from 'terminal-link';
 import {execa} from 'execa';
 import pMemoize from 'p-memoize';
-import ow from 'ow';
 import chalk from 'chalk';
 import Version from './version.js';
 import * as git from './git-util.js';
 import * as npm from './npm/util.js';
 
+export const assert = (condition, message) => {
+	if (!condition) {
+		throw new Error(message);
+	}
+};
+
 export const readPackage = async (packagePath = process.cwd()) => {
 	const packageResult = await readPackageUp({cwd: packagePath});
 
@@ -62,7 +67,7 @@ export const linkifyCommitRange = (url, commitRange) => {
 
 /** @type {(config: import('./package-manager/types.js').PackageManagerConfig) => Promise<string>} */
 export const getTagVersionPrefix = pMemoize(async config => {
-	ow(config, ow.object.hasKeys('tagVersionPrefixCommand'));
+	assert(config && Object.hasOwn(config, 'tagVersionPrefixCommand'), 'Config is missing key `tagVersionPrefixCommand`');
 
 	try {
 		const {stdout} = await execa(...config.tagVersionPrefixCommand);
@@ -132,7 +137,7 @@ export const getNewDependencies = async (newPackage, rootDirectory) => {
 
 /** @type {(config: import('./package-manager/types.js').PackageManagerConfig) => Promise<string>} */
 export const getPreReleasePrefix = pMemoize(async config => {
-	ow(config, ow.object.hasKeys('cli'));
+	assert(config && Object.hasOwn(config, 'cli'), 'Config is missing key `cli`');
 
 	try {
 		const {stdout} = await execa(config.cli, ['config', 'get', 'preid']);
diff --git a/test/npm/util/collaborators.js b/test/npm/util/collaborators.js
index 074e4195..8afffd28 100644
--- a/test/npm/util/collaborators.js
+++ b/test/npm/util/collaborators.js
@@ -9,7 +9,7 @@ const createFixture = _createFixture('../../../source/npm/util.js', import.meta.
 test('package.name not a string', async t => {
 	await t.throwsAsync(
 		npm.collaborators({name: 1}),
-		{message: 'Expected argument to be of type `string` but received type `number`'},
+		{message: 'Package name is required'},
 	);
 });
 
diff --git a/test/npm/util/prerelease-tags.js b/test/npm/util/prerelease-tags.js
index a620cfd9..6424e414 100644
--- a/test/npm/util/prerelease-tags.js
+++ b/test/npm/util/prerelease-tags.js
@@ -9,7 +9,7 @@ const createFixture = _createFixture('../../../source/npm/util.js', import.meta.
 test('packageName not a string', async t => {
 	await t.throwsAsync(
 		npm.prereleaseTags(1),
-		{message: 'Expected argument to be of type `string` but received type `number`'},
+		{message: 'Package name is required'},
 	);
 });
 
diff --git a/test/util/get-pre-release-prefix.js b/test/util/get-pre-release-prefix.js
index 84cbedba..0a69d8d8 100644
--- a/test/util/get-pre-release-prefix.js
+++ b/test/util/get-pre-release-prefix.js
@@ -1,6 +1,5 @@
 import process from 'node:process';
 import test from 'ava';
-import {stripIndent} from 'common-tags';
 import {_createFixture} from '../_helpers/stub-execa.js';
 import {getPreReleasePrefix as originalGetPreReleasePrefix} from '../../source/util.js';
 
@@ -50,17 +49,12 @@ test('returns empty string if not set - yarn', createFixture, [{
 test('no options passed', async t => {
 	await t.throwsAsync(
 		originalGetPreReleasePrefix(),
-		{
-			message: stripIndent`
-			Expected argument to be of type \`object\` but received type \`undefined\`
-			Expected object to have keys \`["cli"]\`
-		`,
-		},
+		{message: 'Config is missing key `cli`'},
 	);
 
 	await t.throwsAsync(
 		originalGetPreReleasePrefix({}),
-		{message: 'Expected object to have keys `["cli"]`'},
+		{message: 'Config is missing key `cli`'},
 	);
 });
 
diff --git a/test/util/get-tag-version-prefix.js b/test/util/get-tag-version-prefix.js
index b14ba9e5..90bb1e28 100644
--- a/test/util/get-tag-version-prefix.js
+++ b/test/util/get-tag-version-prefix.js
@@ -1,5 +1,4 @@
 import test from 'ava';
-import {stripIndent} from 'common-tags';
 import {_createFixture} from '../_helpers/stub-execa.js';
 import {getTagVersionPrefix as originalGetTagVersionPrefix} from '../../source/util.js';
 import {npmConfig, yarnConfig} from '../../source/package-manager/configs.js';
@@ -40,16 +39,11 @@ test('defaults to "v" when command fails', createFixture, [{
 test('no options passed', async t => {
 	await t.throwsAsync(
 		originalGetTagVersionPrefix(),
-		{
-			message: stripIndent`
-			Expected argument to be of type \`object\` but received type \`undefined\`
-			Expected object to have keys \`["tagVersionPrefixCommand"]\`
-		`,
-		},
+		{message: 'Config is missing key `tagVersionPrefixCommand`'},
 	);
 
 	await t.throwsAsync(
 		originalGetTagVersionPrefix({}),
-		{message: 'Expected object to have keys `["tagVersionPrefixCommand"]`'},
+		{message: 'Config is missing key `tagVersionPrefixCommand`'},
 	);
 });