diff --git a/client/src/pages/userProfile/UserProfilePage.vue b/client/src/pages/userProfile/UserProfilePage.vue
index cf27137e..b2d49465 100644
--- a/client/src/pages/userProfile/UserProfilePage.vue
+++ b/client/src/pages/userProfile/UserProfilePage.vue
@@ -55,7 +55,12 @@ onMounted(() => {
             <p class="mb-2">{{ user.email }}</p>
             <p class="text-gray-800">
               {{ $t("a.Teilnehmer") }}
-              <span v-if="user.optional_attendance" data-cy="optional-attendance">
+              <span
+                v-if="
+                  user.optional_attendance.some((id: string) => id === courseSession.id)
+                "
+                data-cy="optional-attendance"
+              >
                 {{ $t("a.Optionale Anwesenheit") }}
               </span>
             </p>
diff --git a/server/vbv_lernwelt/api/tests/test_profile.py b/server/vbv_lernwelt/api/tests/test_profile.py
index b5b68f70..453e479f 100644
--- a/server/vbv_lernwelt/api/tests/test_profile.py
+++ b/server/vbv_lernwelt/api/tests/test_profile.py
@@ -71,6 +71,6 @@ class ProfileViewTest(APITestCase):
                 "organisation_postal_code": "",
                 "organisation_city": "",
                 "organisation_country": None,
-                "optional_attendance": False,
+                "optional_attendance": [],
             },
         )
diff --git a/server/vbv_lernwelt/core/serializers.py b/server/vbv_lernwelt/core/serializers.py
index d099c6ee..ba43e949 100644
--- a/server/vbv_lernwelt/core/serializers.py
+++ b/server/vbv_lernwelt/core/serializers.py
@@ -111,9 +111,10 @@ class UserSerializer(serializers.ModelSerializer):
         return [str(_id) for _id in (supervisor_in_session_ids | expert_in_session_ids)]
 
     def get_optional_attendance(self, obj: User) -> bool:
-        return CourseSessionUser.objects.filter(
+        optional_attendance_ids = CourseSessionUser.objects.filter(
             user=obj, optional_attendance=True
         ).values_list("course_session__id", flat=True)
+        return [str(id) for id in optional_attendance_ids]
 
     def update(self, instance, validated_data):
         country_data = validated_data.pop("country", None)