diff --git a/lib/ansible/playbook/play_context.py b/lib/ansible/playbook/play_context.py
index 2ff06857f33..34b9affade6 100644
--- a/lib/ansible/playbook/play_context.py
+++ b/lib/ansible/playbook/play_context.py
@@ -519,7 +519,7 @@ class PlayContext(Base):
 
                 var_val = getattr(self, prop)
                 for var_opt in var_list:
-                    if var_opt not in variables:
+                    if var_opt not in variables and var_val is not None:
                         variables[var_opt] = var_val
             except AttributeError:
                 continue