diff --git a/python/samba/gp/gp_centrify_crontab_ext.py b/python/samba/gp/gp_centrify_crontab_ext.py
index e8ffd8bec9f..e532416d224 100644
--- a/python/samba/gp/gp_centrify_crontab_ext.py
+++ b/python/samba/gp/gp_centrify_crontab_ext.py
@@ -16,9 +16,11 @@
 
 import os, re
 from subprocess import Popen, PIPE
-from samba.gp.gpclass import gp_pol_ext, drop_privileges, gp_file_applier
-from hashlib import blake2b
+from samba.gp.gpclass import gp_pol_ext, drop_privileges, gp_file_applier, \
+    gp_misc_applier
 from tempfile import NamedTemporaryFile
+from samba.gp.gp_scripts_ext import fetch_crontab, install_crontab, \
+    install_user_crontab
 
 intro = '''
 ### autogenerated by samba
@@ -92,73 +94,44 @@ class gp_centrify_crontab_ext(gp_pol_ext, gp_file_applier):
                     output[str(self)].append(e.data)
         return output
 
-def fetch_crontab(username):
-    p = Popen(['crontab', '-l', '-u', username], stdout=PIPE, stderr=PIPE)
-    out, err = p.communicate()
-    if p.returncode != 0:
-        raise RuntimeError('Failed to read the crontab: %s' % err)
-    m = re.findall('%s(.*)%s' % (intro, end), out.decode(), re.DOTALL)
-    if len(m) == 1:
-        entries = m[0].strip().split('\n')
-    else:
-        entries = []
-    m = re.findall('(.*)%s.*%s(.*)' % (intro, end), out.decode(), re.DOTALL)
-    if len(m) == 1:
-        others = '\n'.join([l.strip() for l in m[0]])
-    else:
-        others = out.decode()
-    return others, entries
+class gp_user_centrify_crontab_ext(gp_centrify_crontab_ext, gp_misc_applier):
+    def unapply(self, guid, attribute, entry):
+        others, entries = fetch_crontab(self.username)
+        if entry in entries:
+            entries.remove(entry)
+            install_user_crontab(self.username, others, entries)
+        self.cache_remove_attribute(guid, attribute)
 
-def install_crontab(fname, username):
-    p = Popen(['crontab', fname, '-u', username], stdout=PIPE, stderr=PIPE)
-    _, err = p.communicate()
-    if p.returncode != 0:
-        raise RuntimeError('Failed to install crontab: %s' % err)
+    def apply(self, guid, attribute, entry):
+        old_val = self.cache_get_attribute_value(guid, attribute)
+        others, entries = fetch_crontab(self.username)
+        if not old_val or entry not in entries:
+            entries.append(entry)
+            install_user_crontab(self.username, others, entries)
+            self.cache_add_attribute(guid, attribute, entry)
 
-class gp_user_centrify_crontab_ext(gp_centrify_crontab_ext):
     def process_group_policy(self, deleted_gpo_list, changed_gpo_list):
         for guid, settings in deleted_gpo_list:
-            self.gp_db.set_guid(guid)
             if str(self) in settings:
-                others, entries = fetch_crontab(self.username)
                 for attribute, entry in settings[str(self)].items():
-                    if entry in entries:
-                        entries.remove(entry)
-                    self.gp_db.delete(str(self), attribute)
-                with NamedTemporaryFile() as f:
-                    if len(entries) > 0:
-                        f.write('\n'.join([others, intro,
-                                '\n'.join(entries), end]).encode())
-                    else:
-                        f.write(others.encode())
-                    f.flush()
-                    install_crontab(f.name, self.username)
-            self.gp_db.commit()
+                    self.unapply(guid, attribute, entry)
 
         for gpo in changed_gpo_list:
             if gpo.file_sys_path:
                 section = \
                     'Software\\Policies\\Centrify\\UnixSettings\\CrontabEntries'
-                self.gp_db.set_guid(gpo.name)
                 pol_file = 'USER/Registry.pol'
                 path = os.path.join(gpo.file_sys_path, pol_file)
                 pol_conf = drop_privileges('root', self.parse, path)
                 if not pol_conf:
                     continue
+                attrs = []
                 for e in pol_conf.entries:
                     if e.keyname == section and e.data.strip():
-                        attribute = blake2b(e.data.encode()).hexdigest()
-                        old_val = self.gp_db.retrieve(str(self), attribute)
-                        others, entries = fetch_crontab(self.username)
-                        if not old_val or e.data not in entries:
-                            entries.append(e.data)
-                            with NamedTemporaryFile() as f:
-                                f.write('\n'.join([others, intro,
-                                        '\n'.join(entries), end]).encode())
-                                f.flush()
-                                install_crontab(f.name, self.username)
-                            self.gp_db.store(str(self), attribute, e.data)
-                        self.gp_db.commit()
+                        attribute = self.generate_attribute(e.data)
+                        attrs.append(attribute)
+                        self.apply(gpo.name, attribute, e.data)
+                self.clean(gpo.name, keep=attrs)
 
     def rsop(self, gpo):
         return super().rsop(gpo, target='USER')
diff --git a/selftest/knownfail.d/gpo b/selftest/knownfail.d/gpo
deleted file mode 100644
index 94ba8c2b5e0..00000000000
--- a/selftest/knownfail.d/gpo
+++ /dev/null
@@ -1 +0,0 @@
-^samba.tests.gpo.samba.tests.gpo.GPOTests.test_gp_user_centrify_crontab_ext