diff --git a/lib/ansible/playbook/play_context.py b/lib/ansible/playbook/play_context.py
index 0d595bef852..d3f738fffe9 100644
--- a/lib/ansible/playbook/play_context.py
+++ b/lib/ansible/playbook/play_context.py
@@ -216,7 +216,7 @@ class PlayContext(Base):
     _force_handlers = FieldAttribute(isa='bool', default=False)
     _start_at_task = FieldAttribute(isa='string')
     _step = FieldAttribute(isa='bool', default=False)
-    _diff = FieldAttribute(isa='bool', default=C.DIFF_ALWAYS)
+    _diff = FieldAttribute(isa='bool')
 
     # Fact gathering settings
     _gather_subset = FieldAttribute(isa='string', default=C.DEFAULT_GATHER_SUBSET)