diff --git a/src/collective/task/browser/guards.py b/src/collective/task/browser/guards.py
deleted file mode 100644
index c7e4f9e..0000000
--- a/src/collective/task/browser/guards.py
+++ /dev/null
@@ -1,33 +0,0 @@
-from five import grok
-
-from plone import api
-
-from collective.task.content.task import ITask
-
-
-class BaseSubtaskGuard(grok.View):
-    """Base class for 'subtask' guards views"""
-    grok.context(ITask)
-    grok.baseclass()
-    grok.require("zope2.View")
-
-    def update(self):
-        """Create subtasks states list"""
-        subtasks = self.context.listFolderContents()
-        self.subtasks_states = [api.content.get_state(subtask) for subtask in subtasks]
-
-
-class SubtaskDoneGuard(BaseSubtaskGuard):
-    """Returns True if the subtask is done"""
-    grok.name("subtask_done")
-
-    def render(self):
-        return 'done' in self.subtasks_states
-
-
-class SubtasksAbandonedGuard(BaseSubtaskGuard):
-    """Returns True is the subtask is abandoned"""
-    grok.name("subtasks_abandoned")
-
-    def render(self):
-        return set(['abandoned']) == set(self.subtasks_states)
diff --git a/src/collective/task/content/task.py b/src/collective/task/content/task.py
index d98cd6f..09c2bd0 100644
--- a/src/collective/task/content/task.py
+++ b/src/collective/task/content/task.py
@@ -1,6 +1,7 @@
 from zope.interface import implements
 
 from plone.dexterity.content import Container
+from plone import api
 
 from collective.task.interfaces import IBaseTask, IDeadline
 
@@ -17,3 +18,13 @@ class Task(Container):
     meta_type = 'task'
     # disable local roles inheritance
     __ac_local_roles_block__ = True
+
+    def get_subtask_states(self):
+        subtasks = self.listFolderContents()
+        return [api.content.get_state(subtask) for subtask in subtasks]
+
+    def subtasks_abandoned(self):
+        return set(['abandoned']) == set(self.get_subtask_states())
+
+    def subtasks_done(self):
+        return set(['done']) == set(self.get_subtask_states())
diff --git a/src/collective/task/profiles/default/workflows/task_workflow/definition.xml b/src/collective/task/profiles/default/workflows/task_workflow/definition.xml
index ebc3a4e..3b5d2cb 100644
--- a/src/collective/task/profiles/default/workflows/task_workflow/definition.xml
+++ b/src/collective/task/profiles/default/workflows/task_workflow/definition.xml
@@ -127,13 +127,13 @@
  <transition transition_id="subtask-abandoned" title="Subtask abandoned" new_state="todo" trigger="USER" before_script="" after_script="">
   <action url="" category="workflow" icon="" i18n:translate="">Subtask abandoned</action>
   <guard>
-   <guard-expression>here/@@subtasks_abandoned</guard-expression>
+   <guard-expression>python: here.subtasks_abandoned()</guard-expression>
   </guard>
  </transition>
  <transition transition_id="subtask-done" title="Subtask done" new_state="done" trigger="USER" before_script="" after_script="">
   <action url="" category="workflow" icon="" i18n:translate="">Subtask done</action>
   <guard>
-   <guard-expression>here/@@subtask_done</guard-expression>
+   <guard-expression>python: here.subtasks_done()</guard-expression>
   </guard>
  </transition>
  <transition transition_id="take-responsibility" title="Take responsibility" new_state="in-progress" trigger="USER" before_script="" after_script="">