diff --git a/input/models.py b/input/models.py
index 45f38e9..5193d7f 100755
--- a/input/models.py
+++ b/input/models.py
@@ -203,6 +203,14 @@ class ProjectCategoryField(models.ManyToManyField):
 
         return super().formfield(**kwargs)
 
+    def save_form_data(self, instance, data):
+        data = list(data)
+
+        with suppress(ValueError):
+            data.remove(self.remote_field.model.other)
+
+        return super().save_form_data(instance, data)
+
 
 class Project(Volunteer):
     end_mail_send = models.BooleanField(default=False, verbose_name='Keine Projektabschlussmail schicken')