diff --git a/src/config/configJson.ts b/src/config/configJson.ts
index 44fd87e1..c1773cf3 100644
--- a/src/config/configJson.ts
+++ b/src/config/configJson.ts
@@ -3,7 +3,6 @@ import _ from 'lodash';
 
 import * as constants from '../lib/constants';
 import * as hostUtils from '../lib/host-utils';
-import * as osRelease from '../lib/os-release';
 import { takeGlobalLockRO, takeGlobalLockRW } from '../lib/process-lock';
 import type * as Schema from './schema';
 
@@ -12,17 +11,20 @@ export default class ConfigJsonConfigBackend {
 	private readonly writeLockConfigJson: () => Bluebird.Disposer<() => void>;
 
 	private readonly schema: Schema.Schema;
+	/**
+	 * @deprecated configPath is only set by legacy tests
+	 */
 	private readonly configPath?: string;
 
 	private cache: { [key: string]: unknown } = {};
 
-	private readonly init = _.once(async () =>
-		Object.assign(this.cache, await this.read()),
-	);
+	private readonly init = _.once(async () => {
+		Object.assign(this.cache, await this.read());
+	});
 
 	public constructor(schema: Schema.Schema, configPath?: string) {
-		this.configPath = configPath;
 		this.schema = schema;
+		this.configPath = configPath;
 
 		this.writeLockConfigJson = () =>
 			takeGlobalLockRW('config.json').disposer((release) => release());
@@ -91,6 +93,12 @@ export default class ConfigJsonConfigBackend {
 		return JSON.parse(await hostUtils.readFromBoot(filename, 'utf-8'));
 	}
 
+	/**
+	 * @deprecated Either read the config.json path from lib/constants, or
+	 * pass a validated path to the constructor and fail if no path is passed.
+	 * TODO: Remove this once api-binder tests are migrated. The only
+	 * time configPath is passed to the constructor is in the legacy tests.
+	 */
 	private async path(): Promise<string> {
 		// TODO: Remove this once api-binder tests are migrated. The only
 		// time configPath is passed to the constructor is in the legacy tests.
@@ -98,11 +106,6 @@ export default class ConfigJsonConfigBackend {
 			return this.configPath;
 		}
 
-		const osVersion = await osRelease.getOSVersion(constants.hostOSVersionPath);
-		if (osVersion == null) {
-			throw new Error('Failed to detect OS version!');
-		}
-
 		// The default path in the boot partition
 		return constants.configJsonPath;
 	}
diff --git a/test/integration/config/configJson.spec.ts b/test/integration/config/configJson.spec.ts
new file mode 100644
index 00000000..39c8f1b9
--- /dev/null
+++ b/test/integration/config/configJson.spec.ts
@@ -0,0 +1,101 @@
+import { expect } from 'chai';
+import { testfs } from 'mocha-pod';
+import { promises as fs } from 'fs';
+
+import ConfigJsonConfigBackend from '~/src/config/configJson';
+import { schema } from '~/src/config/schema';
+
+describe('ConfigJsonConfigBackend', () => {
+	const CONFIG_PATH = '/mnt/boot/config.json';
+	let configJsonConfigBackend: ConfigJsonConfigBackend;
+
+	beforeEach(() => {
+		configJsonConfigBackend = new ConfigJsonConfigBackend(schema);
+	});
+
+	it('should get value for config.json key', async () => {
+		await testfs({
+			[CONFIG_PATH]: JSON.stringify({
+				apiEndpoint: 'foo',
+			}),
+			'/mnt/root/etc/os-release': testfs.from('test/data/etc/os-release'),
+		}).enable();
+
+		expect(await configJsonConfigBackend.get('apiEndpoint')).to.equal('foo');
+
+		await testfs.restore();
+	});
+
+	it('should set value for config.json key', async () => {
+		await testfs({
+			[CONFIG_PATH]: JSON.stringify({
+				apiEndpoint: 'foo',
+			}),
+			'/mnt/root/etc/os-release': testfs.from('test/data/etc/os-release'),
+		}).enable();
+
+		await configJsonConfigBackend.set({
+			apiEndpoint: 'bar',
+		});
+
+		expect(await configJsonConfigBackend.get('apiEndpoint')).to.equal('bar');
+
+		await testfs.restore();
+	});
+
+	// The following test cases may be unnecessary as they test cases where another party
+	// writes to config.json directly (instead of through setting config vars on the API).
+	it('should get cached value even if actual value has changed', async () => {
+		await testfs({
+			[CONFIG_PATH]: JSON.stringify({
+				apiEndpoint: 'foo',
+			}),
+			'/mnt/root/etc/os-release': testfs.from('test/data/etc/os-release'),
+		}).enable();
+
+		// The cached value should be returned
+		expect(await configJsonConfigBackend.get('apiEndpoint')).to.equal('foo');
+
+		// Change the value in the file
+		await fs.writeFile(
+			CONFIG_PATH,
+			JSON.stringify({
+				apiEndpoint: 'bar',
+			}),
+		);
+
+		// Unintended behavior: the cached value should not be overwritten
+		expect(await configJsonConfigBackend.get('apiEndpoint')).to.equal('foo');
+
+		await testfs.restore();
+	});
+
+	it('should set value and refresh cache to equal new value', async () => {
+		await testfs({
+			[CONFIG_PATH]: JSON.stringify({
+				apiEndpoint: 'foo',
+			}),
+			'/mnt/root/etc/os-release': testfs.from('test/data/etc/os-release'),
+		}).enable();
+
+		expect(await configJsonConfigBackend.get('apiEndpoint')).to.equal('foo');
+
+		await fs.writeFile(
+			CONFIG_PATH,
+			JSON.stringify({
+				apiEndpoint: 'bar',
+			}),
+		);
+
+		// Unintended behavior: cached value should not have been updated
+		expect(await configJsonConfigBackend.get('apiEndpoint')).to.equal('foo');
+
+		await configJsonConfigBackend.set({
+			apiEndpoint: 'baz',
+		});
+
+		expect(await configJsonConfigBackend.get('apiEndpoint')).to.equal('baz');
+
+		await testfs.restore();
+	});
+});