diff --git a/tests/unit/CachingIteratorAggregateTest.php b/tests/unit/CachingIteratorAggregateTest.php
index fb7920b..5f690d9 100644
--- a/tests/unit/CachingIteratorAggregateTest.php
+++ b/tests/unit/CachingIteratorAggregateTest.php
@@ -9,6 +9,7 @@
 
 namespace tests\loophp\iterators;
 
+use Generator;
 use loophp\iterators\CachingIteratorAggregate;
 use PHPUnit\Framework\TestCase;
 
@@ -20,16 +21,38 @@ final class CachingIteratorAggregateTest extends TestCase
 {
     public function testWithAGenerator(): void
     {
-        $input = static function () {
+        $input = static function (): Generator {
+            yield true => true;
+
+            yield false => false;
+
+            yield ['a'] => ['a'];
+
             yield from range('a', 'c');
         };
 
         $iterator = (new CachingIteratorAggregate($input()));
 
-        foreach ($iterator as $key => $value);
+        $a = $b = [];
+
+        foreach ($iterator as $key => $value) {
+            $a[] = [$key, $value];
+        }
+
+        foreach ($iterator as $key => $value) {
+            $b[] = [$key, $value];
+        }
 
-        foreach ($iterator as $key => $value);
+        $expected = [
+            [true, true],
+            [false, false],
+            [['a'], ['a']],
+            [0, 'a'],
+            [1, 'b'],
+            [2, 'c'],
+        ];
 
-        $this->expectNotToPerformAssertions();
+        self::assertEquals($expected, $a);
+        self::assertTrue($a === $b);
     }
 }