diff --git a/app/Livewire/Forms/ProfileForm.php b/app/Livewire/Forms/ProfileForm.php
index e27dfba..df413f6 100644
--- a/app/Livewire/Forms/ProfileForm.php
+++ b/app/Livewire/Forms/ProfileForm.php
@@ -17,6 +17,20 @@ class ProfileForm extends Form
 
     public ?EinundzwanzigPleb $currentPleb;
 
+    public function updatingEmail(mixed $value): void
+    {
+        if (! is_string($value) && ! is_null($value)) {
+            abort(422);
+        }
+    }
+
+    public function updatingNip05Handle(mixed $value): void
+    {
+        if (! is_string($value) && ! is_null($value)) {
+            abort(422);
+        }
+    }
+
     public function setEmail(EinundzwanzigPleb $currentPleb): void
     {
         $this->currentPleb = $currentPleb;
diff --git a/resources/views/livewire/association/profile.blade.php b/resources/views/livewire/association/profile.blade.php
index c289f2c..910d49e 100644
--- a/resources/views/livewire/association/profile.blade.php
+++ b/resources/views/livewire/association/profile.blade.php
@@ -147,6 +147,15 @@ new class extends Component {
         ]);
     }
 
+    public function updatingFax(mixed $value): void
+    {
+        if (! is_string($value)) {
+            $this->skipRender();
+
+            abort(422);
+        }
+    }
+
     public function updatedFax(): void
     {
         $this->js('alert("Markus Turm wird sich per Fax melden!")');
diff --git a/tests/Feature/Livewire/Association/ProfileTest.php b/tests/Feature/Livewire/Association/ProfileTest.php
index 35665ad..7bf7258 100644
--- a/tests/Feature/Livewire/Association/ProfileTest.php
+++ b/tests/Feature/Livewire/Association/ProfileTest.php
@@ -6,6 +6,24 @@ use App\Support\NostrAuth;
 use Illuminate\Support\Facades\Http;
 use Livewire\Livewire;
 
+it('rejects non-string values for the fax field', function () {
+    Livewire::test('association.profile')
+        ->set('fax', [])
+        ->assertStatus(422);
+});
+
+it('rejects non-string values for the email field', function () {
+    Livewire::test('association.profile')
+        ->set('profileForm.email', [])
+        ->assertStatus(422);
+});
+
+it('rejects non-string values for the nip05Handle field', function () {
+    Livewire::test('association.profile')
+        ->set('profileForm.nip05Handle', [])
+        ->assertStatus(422);
+});
+
 it('handles nostr login correctly', function () {
     $pleb = EinundzwanzigPleb::factory()->create();