diff --git a/input/forms.py b/input/forms.py
index d7d2d18..4059d72 100755
--- a/input/forms.py
+++ b/input/forms.py
@@ -5,6 +5,7 @@ from django.forms import ModelForm
 from django.forms.renderers import DjangoTemplates
 from django.utils.html import format_html
 from django.utils.safestring import mark_safe
+from django.utils.translation import gettext_lazy as trans
 
 from .models import (
     Project,
@@ -285,6 +286,27 @@ class LiteratureForm(TermsForm):
     class Media:
         js = ('dropdown/js/literature.js',)
 
+    def clean(self):
+        cleaned_data = TermsForm.clean(self)
+
+        if self.errors:
+            return cleaned_data
+
+        return self.clean_selfbuy_fields(cleaned_data)
+
+    def clean_selfbuy_fields(self, cleaned_data):
+        if cleaned_data['selfbuy'] == 'TRUE':
+            cleaned_data['selfbuy_data'] = ''
+            cleaned_data['selfbuy_give_data'] = False
+        else:
+            if not cleaned_data.get('selfbuy_data'):
+                self.add_error('selfbuy_data', trans('This field is required.'))
+
+            if not cleaned_data.get('selfbuy_give_data'):
+                self.add_error('selfbuy_give_data', trans('This field is required.'))
+
+        return cleaned_data
+
 
 ADULT_CHOICES = {
     'TRUE': mark_safe('Ich bin volljährig.'),
diff --git a/input/tests/views.py b/input/tests/views.py
index aee69c9..dc19d14 100644
--- a/input/tests/views.py
+++ b/input/tests/views.py
@@ -99,8 +99,8 @@ class AnonymousViewTestCase(TestCase):
             'info': 'Test',
             'source': 'Test',
             'notes': '',
-            'selfbuy': 'TRUE',
-            'selfbuy_data': 'NONE',
+            'selfbuy': 'FALSE',
+            'selfbuy_data': 'Test',
             'selfbuy_give_data': True,
             'check': True,
             'terms_accepted': True,
@@ -113,8 +113,8 @@ class AnonymousViewTestCase(TestCase):
             'source': 'Test',
             'notes': '',
             'selfbuy': 'TRUE',
-            'selfbuy_data': 'NONE',
-            'selfbuy_give_data': True,
+            'selfbuy_data': '',
+            'selfbuy_give_data': False,
             'check': False,
         })
 
diff --git a/input/views.py b/input/views.py
index 561a2b7..1472fd0 100755
--- a/input/views.py
+++ b/input/views.py
@@ -252,14 +252,7 @@ class ApplicationView(FormView):
 
     def prepare_data(self, form):
         # Collect cleaned data and mark the current type
-
-        data = {**form.cleaned_data, 'choice': self.type_code}
-
-        # Special rule for literature applications
-        if self.type_code == TYPE_LIT and data.get('selfbuy') == 'TRUE':
-            data['selfbuy_give_data'] = 'False'
-
-        return data
+        return {**form.cleaned_data, 'choice': self.type_code}
 
     def save_obj(self, form, data):
         # Save model instance