diff --git a/app/Models/CurrencyExchangeRate.php b/app/Models/CurrencyExchangeRate.php
index 6f06cc8862..e77bb2484c 100644
--- a/app/Models/CurrencyExchangeRate.php
+++ b/app/Models/CurrencyExchangeRate.php
@@ -36,6 +36,9 @@ use Illuminate\Database\Eloquent\Relations\BelongsTo;
  * @property TransactionCurrency $fromCurrency
  * @property TransactionCurrency $toCurrency
  * @property float               $rate
+ * @property Carbon              $date
+ * @property int                 $from_currency_id
+ * @property int                 $to_currency_id
  *
  */
 class CurrencyExchangeRate extends Model
diff --git a/tests/Api/V1/Controllers/CurrencyControllerTest.php b/tests/Api/V1/Controllers/CurrencyControllerTest.php
index d6fb9884b3..c90dada382 100644
--- a/tests/Api/V1/Controllers/CurrencyControllerTest.php
+++ b/tests/Api/V1/Controllers/CurrencyControllerTest.php
@@ -42,7 +42,7 @@ class CurrencyControllerTest extends TestCase
     /**
      *
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         Passport::actingAs($this->user());
diff --git a/tests/Api/V1/Controllers/CurrencyExchangeRateControllerTest.php b/tests/Api/V1/Controllers/CurrencyExchangeRateControllerTest.php
new file mode 100644
index 0000000000..4a0c1c8e04
--- /dev/null
+++ b/tests/Api/V1/Controllers/CurrencyExchangeRateControllerTest.php
@@ -0,0 +1,100 @@
+<?php
+/**
+ * CurrencyExchangeRateControllerTest.php
+ * Copyright (c) 2018 thegrumpydictator@gmail.com
+ *
+ * This file is part of Firefly III.
+ *
+ * Firefly III is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Firefly III is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Firefly III. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace Tests\Api\V1\Controllers;
+
+
+use Carbon\Carbon;
+use FireflyIII\Models\CurrencyExchangeRate;
+use FireflyIII\Models\TransactionCurrency;
+use FireflyIII\Repositories\Currency\CurrencyRepositoryInterface;
+use FireflyIII\Services\Currency\ExchangeRateInterface;
+use Laravel\Passport\Passport;
+use Log;
+use Tests\TestCase;
+
+/**
+ *
+ * Class CurrencyExchangeRateControllerTest
+ */
+class CurrencyExchangeRateControllerTest extends TestCase
+{
+    /**
+     *
+     */
+    public function setUp(): void
+    {
+        parent::setUp();
+        Passport::actingAs($this->user());
+        Log::debug(sprintf('Now in %s.', \get_class($this)));
+
+    }
+
+    /**
+     * @covers \FireflyIII\Api\V1\Controllers\CurrencyExchangeRateController
+     */
+    public function testIndex(): void
+    {
+        // mock repository
+        $repository = $this->mock(CurrencyRepositoryInterface::class);
+        $service    = $this->mock(ExchangeRateInterface::class);
+
+        $rate                   = new CurrencyExchangeRate();
+        $rate->date             = new Carbon();
+        $rate->updated_at       = new Carbon();
+        $rate->created_at       = new Carbon();
+        $rate->rate             = '0.5';
+        $rate->to_currency_id   = 1;
+        $rate->from_currency_id = 2;
+
+        // mock calls:
+        $repository->shouldReceive('setUser')->once();
+        $repository->shouldReceive('findByCodeNull')->withArgs(['EUR'])->andReturn(TransactionCurrency::whereCode('EUR')->first())->once();
+        $repository->shouldReceive('findByCodeNull')->withArgs(['USD'])->andReturn(TransactionCurrency::whereCode('USD')->first())->once();
+        $repository->shouldReceive('getExchangeRate')->andReturn(null)->once();
+        $service->shouldReceive('setUser')->once();
+        $service->shouldReceive('getRate')->once()->andReturn($rate);
+
+        // test API
+        $params   = [
+            'from' => 'EUR',
+            'to'   => 'USD',
+            'date' => '2018-01-01',
+        ];
+        $response = $this->get('/api/v1/cer?' . http_build_query($params));
+        $response->assertStatus(200);
+        $response->assertJson(
+            ['data' => [
+                'rate'  => 0.5,
+                'links' => [
+                    [
+                        'rel' => 'self',
+                        'uri' => '/currency_exchange_rates/',
+                    ],
+                ],
+            ],
+            ]
+        );
+        $response->assertHeader('Content-Type', 'application/vnd.api+json');
+    }
+}
\ No newline at end of file