diff --git a/affiliations-tools/v1/expand.ini b/affiliations-tools/v1/expand.ini
index b59765c..f82208f 100644
--- a/affiliations-tools/v1/expand.ini
+++ b/affiliations-tools/v1/expand.ini
@@ -1,4 +1,6 @@
 # OpenAPI Documentation - JSON format (dot notation)
+mimeType = application/json
+
 post.responses.default.description = Return all objects with enrich fields
 post.responses.default.content.application/json.schema.$ref =  #/components/schemas/JSONStream
 post.summary = Structure one field of each Object as raw affiliation