diff --git a/smash/web/api_views/serialization_utils.py b/smash/web/api_views/serialization_utils.py
new file mode 100644
index 0000000000000000000000000000000000000000..a780e4e015b20764ff3f15097d521209871694fb
--- /dev/null
+++ b/smash/web/api_views/serialization_utils.py
@@ -0,0 +1,10 @@
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+def bool_to_yes_no(val):
+    if val:
+        return "YES"
+    else:
+        return "NO"
diff --git a/smash/web/api_views/subject.py b/smash/web/api_views/subject.py
index ab558c01959f748304588899bebd91204d84ced0..f05f17d00d973fa54dd07ce2900ece744b8f374c 100644
--- a/smash/web/api_views/subject.py
+++ b/smash/web/api_views/subject.py
@@ -5,6 +5,7 @@ from django.db.models import Count, Case, When, Min, Max
 from django.db.models import Q
 from django.http import JsonResponse
 
+from web.api_views.serialization_utils import bool_to_yes_no
 from web.models import StudySubject, Visit, Appointment, Subject, SubjectColumns, StudyColumns, Study, ContactAttempt
 from web.models.constants import SUBJECT_TYPE_CHOICES, GLOBAL_STUDY_ID
 from web.models.study_subject_list import SUBJECT_LIST_GENERIC, SUBJECT_LIST_NO_VISIT, SUBJECT_LIST_REQUIRE_CONTACT, \
@@ -321,13 +322,6 @@ def types(request):
     })
 
 
-def get_yes_no(val):
-    if val:
-        return "YES"
-    else:
-        return "NO"
-
-
 def serialize_subject(study_subject):
     location = ""
     if study_subject.default_location is not None:
@@ -369,7 +363,7 @@ def serialize_subject(study_subject):
     if len(contact_attempts) > 0:
         last_contact_attempt = contact_attempts[0]
         last_contact_attempt_string = last_contact_attempt.datetime_when.strftime(
-            '%Y-%m-%d %H:%M') + "<br/>" + str(last_contact_attempt.worker) + "<br/> Success: " + get_yes_no(
+            '%Y-%m-%d %H:%M') + "<br/>" + str(last_contact_attempt.worker) + "<br/> Success: " + bool_to_yes_no(
             last_contact_attempt.success) + "<br/>" + last_contact_attempt.comment
 
     else:
@@ -385,10 +379,10 @@ def serialize_subject(study_subject):
         "referral": study_subject.referral,
         "default_location": location,
         "flying_team": flying_team,
-        "dead": get_yes_no(study_subject.subject.dead),
-        "resigned": get_yes_no(study_subject.resigned),
-        "postponed": get_yes_no(study_subject.postponed),
-        "information_sent": get_yes_no(study_subject.information_sent),
+        "dead": bool_to_yes_no(study_subject.subject.dead),
+        "resigned": bool_to_yes_no(study_subject.resigned),
+        "postponed": bool_to_yes_no(study_subject.postponed),
+        "information_sent": bool_to_yes_no(study_subject.information_sent),
         "type": study_subject.get_type_display(),
         "id": study_subject.id,
         "visits": serialized_visits,
diff --git a/smash/web/api_views/visit.py b/smash/web/api_views/visit.py
index e426440ad4abdb5615fb9a99f30f2f3902aed725..c2b024c9979360a99eee8eac44ab6e3683a56f29 100644
--- a/smash/web/api_views/visit.py
+++ b/smash/web/api_views/visit.py
@@ -3,6 +3,7 @@ import logging
 from django.contrib.auth.decorators import login_required
 from django.http import JsonResponse
 
+from web.api_views.serialization_utils import bool_to_yes_no
 from web.models import SubjectColumns
 from web.models import Visit, Study, VisitColumns, StudyVisitList
 from web.models.constants import GLOBAL_STUDY_ID
@@ -183,8 +184,8 @@ def serialize_visit(visit):
         "last_name": visit.subject.subject.last_name,
         "datetime_begin": datetime_begin,
         "datetime_end": datetime_end,
-        "is_finished": visit.is_finished,
-        "post_mail_sent": visit.post_mail_sent,
+        "is_finished": bool_to_yes_no(visit.is_finished),
+        "post_mail_sent": bool_to_yes_no(visit.post_mail_sent),
         "visit_number": visit.visit_number,
         "id": visit.id,
     }