diff --git a/program/serializers.py b/program/serializers.py
index 3938ae963d4c74ba98f4b14181db0dd7063e2864..cb94333656cc7eb073fe3d114cd4f2cec6bbb90c 100644
--- a/program/serializers.py
+++ b/program/serializers.py
@@ -1511,7 +1511,10 @@ class PlaylistSerializer(serializers.ModelSerializer):
         ) + read_only_fields
 
     def create(self, validated_data):
-        """Create a new Playlist instance, given the validated data."""
+        """Create a new Playlist instance, given the validated data.
+
+        A ValidationError is raised if a playlist entry is invalid or if multiple null duration
+        entries are present."""
 
         user = self.context["request"].user
         user_is_owner = user in validated_data.get("show").owners.all()
@@ -1543,7 +1546,10 @@ class PlaylistSerializer(serializers.ModelSerializer):
         return playlist
 
     def update(self, instance, validated_data):
-        """Update an existing Playlist instance, given the validated data."""
+        """Update an existing Playlist instance, given the validated data.
+
+        A ValidationError is raised if a playlist entry is invalid or if multiple null duration
+        entries are present."""
 
         user = self.context["request"].user
         user_is_owner = user in instance.show.owners.all()