diff -r e651d5f24cb5 -r b01dd0ef43aa cubicweb/web/controller.py
--- a/cubicweb/web/controller.py	Wed Mar 13 13:37:49 2019 +0100
+++ b/cubicweb/web/controller.py	Thu Mar 14 14:43:18 2019 +0100
@@ -23,7 +23,6 @@
 
 from logilab.mtconverter import xml_escape
 from logilab.common.registry import yes
-from logilab.common.deprecation import deprecated
 
 from cubicweb.appobject import AppObject
 from cubicweb.mail import format_mail
@@ -106,12 +105,6 @@
         if not self._edited_entity:
             self._edited_entity = entity
 
-    @deprecated('[3.18] call view.set_http_cache_headers then '
-                '.is_client_cache_valid() method and return instead')
-    def validate_cache(self, view):
-        view.set_http_cache_headers()
-        self._cw.validate_cache()
-
     def sendmail(self, recipient, subject, body):
         senderemail = self._cw.user.cw_adapt_to('IEmailable').get_email()
         msg = format_mail({'email' : senderemail,