diff --git a/arkindex/documents/serializers/search.py b/arkindex/documents/serializers/search.py
index 6abda38c2bf38b17b10e1ccecbad49fab52835a9..799ade083c065add32fa87094555bedd67b837e4 100644
--- a/arkindex/documents/serializers/search.py
+++ b/arkindex/documents/serializers/search.py
@@ -98,7 +98,7 @@ class CorpusSearchQuerySerializer(serializers.Serializer):
     """))
 
     sources = serializers.MultipleChoiceField(
-        [
+        choices=[
             ("element", "element"),
             ("transcription", "transcription"),
             ("metadata", "metadata"),
diff --git a/requirements.txt b/requirements.txt
index 455a17b66a4e8a27a2e7e74de0c7860ee43c8973..60fad269a3261dab1d912836beca2c03d89921d0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,7 +7,7 @@ django-cors-headers==3.14.0
 django-enumfields==2.1.1
 django-pgtrigger==4.7.0
 django-rq==2.10.1
-djangorestframework==3.12.4
+djangorestframework==3.13.1
 djangorestframework-simplejwt==5.2.2
 docker==7.0.0
 drf-spectacular==0.18.2