diff --git a/tests/LanguageMapOfStringsTest.php b/tests/LanguageMapOfStringsTest.php
index e65934e..10b0eb7 100644
--- a/tests/LanguageMapOfStringsTest.php
+++ b/tests/LanguageMapOfStringsTest.php
@@ -19,6 +19,9 @@ public function testConstruct()
 
         $nonstrict = new LanguageMapOfStrings([0=>[], 'en'=>'hi']);
         $this->assertEquals($map, $nonstrict);
+
+        $map['en'] = null;
+        $this->assertEquals(new LanguageMapOfStrings(), $map);
     }
 
     public function testJson()
diff --git a/tests/SetTest.php b/tests/SetTest.php
index 6c0ca98..011a52e 100644
--- a/tests/SetTest.php
+++ b/tests/SetTest.php
@@ -7,6 +7,7 @@
 
 /**
  * @covers JSKOS\Set
+ * @covers JSKOS\Container
  */
 class SetTest extends \PHPUnit\Framework\TestCase
 {