diff --git a/tests/EdgeCasesTest.php b/tests/EdgeCasesTest.php
index eef714a..5023e24 100644
--- a/tests/EdgeCasesTest.php
+++ b/tests/EdgeCasesTest.php
@@ -78,6 +78,28 @@ public function testFilterAnyFalseValueCustomCallback()
         $this->assertCount(0, $pipeline->toArray());
     }
 
+    public function testNonUniqueKeys()
+    {
+        $pipeline = \Pipeline\map(function () {
+            yield 'foo' => 'bar';
+            yield 'foo' => 'baz';
+        });
+
+        $this->assertSame([
+            'foo' => 'baz',
+        ], iterator_to_array($pipeline));
+
+        $pipeline = \Pipeline\map(function () {
+            yield 'foo' => 'bar';
+            yield 'foo' => 'baz';
+        });
+
+        $this->assertSame([
+            'bar',
+            'baz',
+        ], $pipeline->toArray());
+    }
+
     public function testMapUnprimed()
     {
         $pipeline = new Standard();
diff --git a/tests/ErrorsTest.php b/tests/ErrorsTest.php
index 83fbc02..5f1c547 100644
--- a/tests/ErrorsTest.php
+++ b/tests/ErrorsTest.php
@@ -71,4 +71,21 @@ public function testPipelineInPipelineUsesSelf()
 
         $pipeline->reduce();
     }
+
+    /**
+     * @covers \Pipeline\Standard::unpack()
+     */
+    public function testUnpackNonIterable()
+    {
+        $pipeline = new \Pipeline\Standard();
+
+        $pipeline->map(function () {
+            yield 1;
+            yield [2, 3];
+        })->unpack();
+
+        $this->expectException(Warning::class);
+        $this->expectExceptionMessage('Only arrays and Traversables can be unpacked');
+        $pipeline->toArray();
+    }
 }