diff --git a/tests/Unit/Helpers/AddressesTest.php b/tests/Unit/Helpers/AddressesTest.php
new file mode 100644
index 0000000..42d3513
--- /dev/null
+++ b/tests/Unit/Helpers/AddressesTest.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace Opdavies\Tests\GmailFilterBuilder\Model;
+
+use Opdavies\GmailFilterBuilder\Helpers\Addresses;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Test loading addresses from a separate file.
+ *
+ * @coversDefaultClass \Opdavies\GmailFilterBuilder\Helpers\Addresses
+ */
+class AddressesTest extends TestCase
+{
+    /**
+     * @covers ::load
+     */
+    public function testLoad()
+    {
+        $expected = [
+            'foo@example.com',
+            'bar@example.com'
+        ];
+
+        $this->assertEquals($expected, FakeAddresses::load());
+    }
+}
+
+class FakeAddresses extends Addresses
+{
+    /**
+     * {@inheritdoc}
+     */
+    protected function getDirectoryPath()
+    {
+        return __DIR__ . '/../../stubs/';
+    }
+}
diff --git a/tests/stubs/my-addresses.php b/tests/stubs/my-addresses.php
new file mode 100644
index 0000000..5483f20
--- /dev/null
+++ b/tests/stubs/my-addresses.php
@@ -0,0 +1,6 @@
+<?php
+
+return [
+    'foo@example.com',
+    'bar@example.com',
+];