diff --git a/lib/gui/app/models/settings.ts b/lib/gui/app/models/settings.ts
index a8bf2a6c..7deb1f11 100644
--- a/lib/gui/app/models/settings.ts
+++ b/lib/gui/app/models/settings.ts
@@ -92,14 +92,17 @@ async function load(): Promise<void> {
 
 const loaded = load();
 
-export async function set(key: string, value: any): Promise<void> {
+export async function set(
+	key: string,
+	value: any,
+	writeConfigFileFn = writeConfigFile,
+): Promise<void> {
 	debug('set', key, value);
 	await loaded;
 	const previousValue = settings[key];
 	settings[key] = value;
 	try {
-		// Use exports.writeConfigFile() so it can be mocked in tests
-		await exports.writeConfigFile(CONFIG_PATH, settings);
+		await writeConfigFileFn(CONFIG_PATH, settings);
 	} catch (error) {
 		// Revert to previous value if persisting settings failed
 		settings[key] = previousValue;
diff --git a/tests/gui/models/settings.spec.ts b/tests/gui/models/settings.spec.ts
index 3f7bf83a..cab37a74 100644
--- a/tests/gui/models/settings.spec.ts
+++ b/tests/gui/models/settings.spec.ts
@@ -44,16 +44,15 @@ describe('Browser: settings', () => {
 			await settings.set('foo', 'bar');
 			expect(await settings.get('foo')).to.equal('bar');
 
-			const writeConfigFileStub = stub(settings, 'writeConfigFile');
+			const writeConfigFileStub = stub();
 			writeConfigFileStub.returns(Promise.reject(new Error('settings error')));
 
-			const p = settings.set('foo', 'baz');
+			const p = settings.set('foo', 'baz', writeConfigFileStub);
 			await checkError(p, async (error) => {
 				expect(error).to.be.an.instanceof(Error);
 				expect(error.message).to.equal('settings error');
 				expect(await settings.get('foo')).to.equal('bar');
 			});
-			writeConfigFileStub.restore();
 		});
 	});
 
@@ -83,15 +82,17 @@ describe('Browser: settings', () => {
 			await settings.set('foo', 'bar');
 			expect(await settings.get('foo')).to.equal('bar');
 
-			const writeConfigFileStub = stub(settings, 'writeConfigFile');
+			const writeConfigFileStub = stub();
 			writeConfigFileStub.returns(Promise.reject(new Error('settings error')));
 
-			await checkError(settings.set('foo', 'baz'), async (error) => {
-				expect(error).to.be.an.instanceof(Error);
-				expect(error.message).to.equal('settings error');
-				expect(await settings.get('foo')).to.equal('bar');
-			});
-			writeConfigFileStub.restore();
+			await checkError(
+				settings.set('foo', 'baz', writeConfigFileStub),
+				async (error) => {
+					expect(error).to.be.an.instanceof(Error);
+					expect(error.message).to.equal('settings error');
+					expect(await settings.get('foo')).to.equal('bar');
+				},
+			);
 		});
 	});
 });