diff --git a/src/senaite/patient/content/fields.py b/src/senaite/patient/content/fields.py
index 65d0008..d158101 100644
--- a/src/senaite/patient/content/fields.py
+++ b/src/senaite/patient/content/fields.py
@@ -30,6 +30,7 @@
 from senaite.patient.browser.widgets import TemporaryIdentifierWidget
 from senaite.patient.config import AUTO_ID_MARKER
 from senaite.patient.config import PATIENT_CATALOG
+from senaite.patient.interfaces import IAgeDateOfBirthField
 from zope.interface import implementer