diff --git a/modules/ppcp-button/src/Helper/DisabledFundingSources.php b/modules/ppcp-button/src/Helper/DisabledFundingSources.php
index acab7d5f7..fc60ba96b 100644
--- a/modules/ppcp-button/src/Helper/DisabledFundingSources.php
+++ b/modules/ppcp-button/src/Helper/DisabledFundingSources.php
@@ -53,7 +53,7 @@ class DisabledFundingSources {
 	 * @return array|int[]|mixed|string[]
 	 * @throws NotFoundException When the setting is not found.
 	 */
-	public function sources( $context ) {
+	public function sources( string $context ) {
 		$disable_funding = $this->settings->has( 'disable_funding' )
 			? $this->settings->get( 'disable_funding' )
 			: array();
diff --git a/tests/PHPUnit/Button/Helper/DisabledFundingSourcesTest.php b/tests/PHPUnit/Button/Helper/DisabledFundingSourcesTest.php
new file mode 100644
index 000000000..7185a2255
--- /dev/null
+++ b/tests/PHPUnit/Button/Helper/DisabledFundingSourcesTest.php
@@ -0,0 +1,95 @@
+<?php
+declare(strict_types=1);
+
+namespace WooCommerce\PayPalCommerce\Button\Helper;
+
+use Mockery;
+use WC_Payment_Gateways;
+use WooCommerce;
+use WooCommerce\PayPalCommerce\TestCase;
+use WooCommerce\PayPalCommerce\WcGateway\Settings\Settings;
+use function Brain\Monkey\Functions\when;
+
+class DisabledFundingSourcesTest extends TestCase
+{
+	private $settings;
+
+	public function setUp(): void
+	{
+		parent::setUp();
+
+		$this->settings = Mockery::mock(Settings::class);
+	}
+
+	public function test_is_checkout_true_does_not_add_card()
+	{
+		$sut = new DisabledFundingSources($this->settings, []);
+
+		$this->setExpectations();
+		$this->setWcPaymentGateways();
+
+		when('is_checkout')->justReturn(true);
+
+		$this->assertEquals([], $sut->sources(''));
+	}
+
+	public function test_is_checkout_false_adds_card()
+	{
+		$sut = new DisabledFundingSources($this->settings, []);
+
+		$this->setExpectations();
+		$this->setWcPaymentGateways();
+
+		when('is_checkout')->justReturn(false);
+
+		$this->assertEquals(['card'], $sut->sources('checkout-block'));
+	}
+
+	public function test_checkout_block_context_adds_source()
+	{
+		$sut = new DisabledFundingSources($this->settings, [
+			'card' => 'Credit or debit cards',
+			'paypal' => 'PayPal',
+			'foo' => 'Bar',
+		]);
+
+		$this->setExpectations();
+		$this->setWcPaymentGateways();
+
+		when('is_checkout')->justReturn(true);
+
+		$this->assertEquals(['foo'], $sut->sources('checkout-block'));
+	}
+
+	private function setExpectations(
+		array $disabledFundings = [],
+		bool  $dccEnambled = true
+	): void
+	{
+		$this->settings->shouldReceive('has')
+			->with('disable_funding')
+			->andReturn(true);
+
+		$this->settings->shouldReceive('get')
+			->with('disable_funding')
+			->andReturn($disabledFundings);
+
+		$this->settings->shouldReceive('has')
+			->with('dcc_enabled')
+			->andReturn(true);
+
+		$this->settings->shouldReceive('get')
+			->with('dcc_enabled')
+			->andReturn($dccEnambled);
+	}
+
+	private function setWcPaymentGateways(array $paymentGateways = []): void
+	{
+		$woocommerce = Mockery::mock(WooCommerce::class);
+		$payment_gateways = Mockery::mock(WC_Payment_Gateways::class);
+		when('WC')->justReturn($woocommerce);
+		$woocommerce->payment_gateways = $payment_gateways;
+		$payment_gateways->shouldReceive('get_available_payment_gateways')
+			->andReturn($paymentGateways);
+	}
+}