diff --git a/lib/ansible/playbook/block.py b/lib/ansible/playbook/block.py
index 1b607a1162..20858055d5 100644
--- a/lib/ansible/playbook/block.py
+++ b/lib/ansible/playbook/block.py
@@ -36,7 +36,7 @@ class Block(Base, Become, Conditional, Taggable):
     _always           = FieldAttribute(isa='list', default=[], inherit=False)
 
     # other fields
-    _any_errors_fatal = FieldAttribute(isa='bool')
+    _any_errors_fatal = FieldAttribute(isa='bool', default=False, always_post_validate=True)
     _delegate_to      = FieldAttribute(isa='string')
     _delegate_facts   = FieldAttribute(isa='bool', default=False)
     _name             = FieldAttribute(isa='string', default='')
diff --git a/lib/ansible/playbook/task.py b/lib/ansible/playbook/task.py
index 39a5316654..caa533ee4e 100644
--- a/lib/ansible/playbook/task.py
+++ b/lib/ansible/playbook/task.py
@@ -68,7 +68,7 @@ class Task(Base, Conditional, Taggable, Become):
     _args                 = FieldAttribute(isa='dict', default=dict())
     _action               = FieldAttribute(isa='string')
 
-    _any_errors_fatal     = FieldAttribute(isa='bool')
+    _any_errors_fatal     = FieldAttribute(isa='bool', default=False, always_post_validate=True)
     _async                = FieldAttribute(isa='int', default=0)
     _changed_when         = FieldAttribute(isa='list', default=[])
     _delay                = FieldAttribute(isa='int', default=5)