diff --git a/src/Api.php b/src/Api.php
index 9e457c3..d81bbc8 100644
--- a/src/Api.php
+++ b/src/Api.php
@@ -207,7 +207,7 @@ class Api
             "Fails fetching membership {$membershipId} for {$memberId}",
         );
 
-        return $membership ? new Membership($membership) : null;
+        return $membership ? Membership::from($membership) : null;
     }
 
     public function courses(): Collection
diff --git a/src/Data/Membership.php b/src/Data/Membership.php
index 31e4c3d..0137693 100644
--- a/src/Data/Membership.php
+++ b/src/Data/Membership.php
@@ -3,35 +3,37 @@
 namespace Zoomyboy\LaravelNami\Data;
 
 use Carbon\Carbon;
-use Spatie\DataTransferObject\Attributes\CastWith;
-use Spatie\DataTransferObject\Attributes\MapFrom;
-use Spatie\DataTransferObject\DataTransferObject;
-use Zoomyboy\LaravelNami\Casters\CarbonCaster;
-use Zoomyboy\LaravelNami\Casters\NullableCarbonCaster;
+use Spatie\LaravelData\Attributes\MapInputName;
+use Spatie\LaravelData\Attributes\WithCast;
+use Spatie\LaravelData\Data;
+use Zoomyboy\LaravelNami\Casters\CarbonCast;
 
-class Membership extends DataTransferObject
+class Membership extends Data
 {
-    public ?int $id;
+    public function __construct(
+        public ?int $id,
 
-    #[MapFrom('gruppierungId')]
-    public int $groupId;
+        #[MapInputName('gruppierungId')]
+        public int $groupId,
 
-    #[MapFrom('aktivVon')]
-    #[CastWith(CarbonCaster::class)]
-    public Carbon $startsAt;
+        #[MapInputName('aktivVon')]
+        #[WithCast(CarbonCast::class, format: 'Y-m-d H:i:s')]
+        public Carbon $startsAt,
 
-    #[MapFrom('aktivBis')]
-    #[CastWith(NullableCarbonCaster::class)]
-    public ?Carbon $endsAt;
+        #[MapInputName('aktivBis')]
+        #[WithCast(CarbonCast::class, format: 'Y-m-d H:i:s')]
+        public ?Carbon $endsAt,
 
-    #[MapFrom('taetigkeitId')]
-    public int $activityId;
+        #[MapInputName('taetigkeitId')]
+        public int $activityId,
 
-    #[MapFrom('untergliederungId')]
-    public ?int $subactivityId;
+        #[MapInputName('untergliederungId')]
+        public ?int $subactivityId,
 
-    #[MapFrom('gruppierung')]
-    public ?string $group;
+        #[MapInputName('gruppierung')]
+        public ?string $group,
+    ) {
+    }
 
     public function toNami(): array
     {
@@ -44,16 +46,4 @@ class Membership extends DataTransferObject
             'untergliederungId' => $this->subactivityId,
         ];
     }
-
-    public static function fromArray(array $data): self
-    {
-        return new self([
-            'gruppierungId' => data_get($data, 'groupId'),
-            'id' => data_get($data, 'id'),
-            'aktivVon' => data_get($data, 'startsAt'),
-            'aktivBis' => data_get($data, 'endsAt'),
-            'taetigkeitId' => data_get($data, 'activityId'),
-            'untergliederungId' => data_get($data, 'subactivityId'),
-        ]);
-    }
 }
diff --git a/src/Data/MembershipEntry.php b/src/Data/MembershipEntry.php
index 247d421..f37736a 100644
--- a/src/Data/MembershipEntry.php
+++ b/src/Data/MembershipEntry.php
@@ -5,7 +5,6 @@ namespace Zoomyboy\LaravelNami\Data;
 use Carbon\Carbon;
 use Spatie\LaravelData\Attributes\MapInputName;
 use Spatie\LaravelData\Attributes\WithCast;
-use Spatie\LaravelData\Casts\DateTimeInterfaceCast;
 use Spatie\LaravelData\Data;
 use Zoomyboy\LaravelNami\Casters\CarbonCast;
 use Zoomyboy\LaravelNami\Casters\StringCast;
@@ -19,7 +18,7 @@ class MembershipEntry extends Data
         public string $group,
 
         #[MapInputName('entries_aktivVon')]
-        #[WithCast(DateTimeInterfaceCast::class, format: 'Y-m-d H:i:s')]
+        #[WithCast(CarbonCast::class, format: 'Y-m-d H:i:s')]
         public Carbon $startsAt,
 
         #[MapInputName('entries_aktivBis')]
diff --git a/tests/Unit/Api/MembershipTest.php b/tests/Unit/Api/MembershipTest.php
index ad5c449..34812f6 100644
--- a/tests/Unit/Api/MembershipTest.php
+++ b/tests/Unit/Api/MembershipTest.php
@@ -78,7 +78,7 @@ class MembershipTest extends TestCase
         Carbon::setTestNow(Carbon::parse('2022-02-03 03:00:00'));
         app(MembershipFake::class)->createsSuccessfully(6, 133);
 
-        $membershipId = $this->login()->putMembership(6, Membership::fromArray([
+        $membershipId = $this->login()->putMembership(6, Membership::from([
             'id' => null,
             'subactivityId' => 3,
             'activityId' => 2,
@@ -102,7 +102,7 @@ class MembershipTest extends TestCase
         Carbon::setTestNow(Carbon::parse('2022-02-03 03:00:00'));
         app(MembershipFake::class)->destroysSuccessfully(6, 133);
 
-        $this->login()->deleteMembership(6, Membership::fromArray([
+        $this->login()->deleteMembership(6, Membership::from([
             'id' => 133,
             'subactivityId' => 3,
             'activityId' => 2,
@@ -120,7 +120,7 @@ class MembershipTest extends TestCase
         app(MembershipFake::class)->failsDeleting(6, 133);
         app(MembershipFake::class)->updatesSuccessfully(6, 133);
 
-        $this->login()->deleteMembership(6, Membership::fromArray([
+        $this->login()->deleteMembership(6, Membership::from([
             'id' => 133,
             'subactivityId' => 3,
             'activityId' => 2,
@@ -142,7 +142,7 @@ class MembershipTest extends TestCase
         app(MembershipFake::class)->failsDeleting(6, null);
         app(MembershipFake::class)->updatesSuccessfully(6, null);
 
-        $this->login()->deleteMembership(6, Membership::fromArray([
+        $this->login()->deleteMembership(6, Membership::from([
             'id' => null,
             'subactivityId' => 3,
             'activityId' => 2,