diff --git a/src/Tags/Property.php b/src/Tags/Property.php
index e12382b..58540f4 100644
--- a/src/Tags/Property.php
+++ b/src/Tags/Property.php
@@ -20,7 +20,7 @@ public function render(string $key, $value = null, Collection $tags = null): Htm
         return new HtmlString(
             sprintf(
                 '<meta property="%s" content="%s">',
-                str_replace('property:', null, $key),
+                str_replace('property:', '', $key),
                 $value
             )
         );
diff --git a/tests/TestCase.php b/tests/TestCase.php
index e02cb84..4ec510a 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -56,7 +56,7 @@ public function tearDown(): void
      */
     public function assertRenders(string $expected, $message = ''): void
     {
-        self::assertStringContainsString($expected, $this->service->render(), $message);
+        self::assertStringContainsString($expected, $this->service::render(), $message);
     }
 
     /**
@@ -68,7 +68,7 @@ public function assertRenders(string $expected, $message = ''): void
      */
     public function assertNotRenders(string $expected, $message = ''): void
     {
-        self::assertStringNotContainsString($expected, $this->service->render(), $message);
+        self::assertStringNotContainsString($expected, $this->service::render(), $message);
     }
 
     /**