diff --git a/biolink/datamodel/serializers.py b/biolink/datamodel/serializers.py
index 77b8dcf..3385fcd 100644
--- a/biolink/datamodel/serializers.py
+++ b/biolink/datamodel/serializers.py
@@ -333,7 +333,7 @@
 # text annotate
 token = api.model('Token', {
     'id': fields.String(description='The CURIE for the entity or token'),
-    'category': fields.List(fields.String, description='entity categories'),
+    'categories': fields.List(fields.String, description='entity categories'),
     'terms': fields.List(fields.String, description='terms')
 })
 
diff --git a/requirements.txt b/requirements.txt
index 43d7b3c..9374925 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,6 @@
 prefixcommons>=0.0
-ontobio>=2.7.14
+# ontobio>=2.7.14
+git+https://github.com/monarch-initiative/ontobio.git@baf3b5a7344fe6dda9c3980c8d472655431cb5df#egg=ontobio
 pip>=9.0.1
 wheel>0.25.0
 markupsafe==2.0.1