diff --git a/tests/src/MapUpdaterTest.php b/tests/src/MapUpdaterTest.php
index d07d2e1c..a814a87d 100644
--- a/tests/src/MapUpdaterTest.php
+++ b/tests/src/MapUpdaterTest.php
@@ -142,7 +142,7 @@ public function testLoadMapFromFreedesktopInvalidFile(): void
     public function testEmptyMapNotWriteable(): void
     {
         $this->expectException('LogicException');
-        $this->assertNull($this->newMap->getFileName());
+        $this->assertSame('', $this->newMap->getFileName());
     }
 
     public function testWriteMapToPhpClassFile(): void
diff --git a/tests/src/TypeTest.php b/tests/src/TypeTest.php
index b8699324..8e8a605b 100644
--- a/tests/src/TypeTest.php
+++ b/tests/src/TypeTest.php
@@ -497,10 +497,10 @@ public function testParseMalformed(string $type): void
     public function testParseAgain(): void
     {
         $mt = new Type('application/ogg;description=Hello there!;asd=fgh');
-        $this->assertSame(2, count($mt->getParameters()));
+        $this->assertCount(2, $mt->getParameters());
 
         $mt = new Type('text/plain;hello=there!');
-        $this->assertSame(1, count($mt->getParameters()));
+        $this->assertCount(1, $mt->getParameters());
     }
 
     public function testGetDescription(): void
@@ -726,6 +726,6 @@ public static function getDefaultExtensionFailProvider()
     public function testGetDefaultExtensionFail(string $type): void
     {
         $this->expectException(MappingException::class);
-        $this->assertNull((new Type($type))->getDefaultExtension());
+        $this->assertSame('', (new Type($type))->getDefaultExtension());
     }
 }