diff --git a/src/Member.php b/src/Member.php
index b0bd721..8ae4a3e 100644
--- a/src/Member.php
+++ b/src/Member.php
@@ -78,14 +78,12 @@ class Member extends Model {
         $this->attributes['gender_id'] = data_get($this->geschlechtMaps, $v, null);
     }
 
-    public function getAttributeValue($key) {
-        $original = parent::getAttributeValue($key);
-
-        if (in_array($key, $this->nullable) && $original === '') {
-            return null;
+    public function setAttribute($key, $value) {
+        if (in_array($key, $this->nullable) && $value === '') {
+            return parent::setAttribute($key, null);
         }
 
-        return $original;
+        return parent::setAttribute($key, $value);
     }
 
 }
diff --git a/tests/Unit/PullMemberTest.php b/tests/Unit/PullMemberTest.php
index 3ed575c..25793ec 100644
--- a/tests/Unit/PullMemberTest.php
+++ b/tests/Unit/PullMemberTest.php
@@ -79,8 +79,8 @@ class PullMemberTest extends TestCase
 
         $group = Nami::group(103);
 
-        $this->assertSame($values[0], $group->member(16)->{$key});
-        $this->assertSame($values[1], $group->member(17)->{$key});
+        $this->assertSame($values[0], $group->member(16)->toArray()[$key]);
+        $this->assertSame($values[1], $group->member(17)->toArray()[$key]);
 
         Http::assertSentCount(5);
     }
@@ -100,10 +100,9 @@ class PullMemberTest extends TestCase
 
         Nami::login();
 
-        $this->assertSame([
-            16 => $values[0],
-            17 => $values[1]
-        ], Nami::group(103)->members()->pluck($key, 'id')->toArray());
+        $member = Nami::group(103)->members();
+        $this->assertSame($values[0], $member->get(0)->toArray()[$key]);
+        $this->assertSame($values[1], $member->get(1)->toArray()[$key]);
 
         Http::assertSentCount(6);
     }
@@ -147,7 +146,7 @@ class PullMemberTest extends TestCase
 
         $group = Nami::group(103);
 
-        $this->assertSame($values[0], $group->member(16)->{$key});
+        $this->assertSame($values[0], $group->member(16)->toArray()[$key]);
 
         Http::assertSentCount(5);
     }