diff --git a/app/serializers/jsonb_hash_serializer.rb b/app/serializers/jsonb_hash_serializer.rb
index f01f29560..8105de7bf 100644
--- a/app/serializers/jsonb_hash_serializer.rb
+++ b/app/serializers/jsonb_hash_serializer.rb
@@ -1,6 +1,6 @@
 class JsonbHashSerializer
   def self.dump(hash)
-    hash.to_json
+    hash.nil? ? '{}' : hash.to_json
   end
 
   def self.load(hash)