diff --git a/src/collective/contact/core/behaviors.py b/src/collective/contact/core/behaviors.py
index 36d8b47..0f5b55c 100644
--- a/src/collective/contact/core/behaviors.py
+++ b/src/collective/contact/core/behaviors.py
@@ -252,6 +252,9 @@ class IBirthday(model.Schema):
         required=False,
         )
 
+alsoProvides(IBirthday, IFormFieldProvider)
+
+
 class IRelatedOrganizations(model.Schema):
     """A content on which we can attach organizations
     """