diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7518d455b58..77bd6aea1f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@ Ansible Changes By Release
 * ec2 inventory script
 * mount module
 * apt module now passes DEBIAN_FRONTEND=noninteractive
+* to catch typos, like 'var' for 'vars', playbooks and tasks now yell on invalid parameters
 
 0.5 "Amsterdam" ------- July 04, 2012
 
diff --git a/lib/ansible/playbook/play.py b/lib/ansible/playbook/play.py
index e2be4748d63..0a56e4b8f66 100644
--- a/lib/ansible/playbook/play.py
+++ b/lib/ansible/playbook/play.py
@@ -32,11 +32,23 @@ class Play(object):
        'tags', 'gather_facts', '_ds', '_handlers', '_tasks'
     ]
 
+    # to catch typos and so forth -- these are userland names
+    # and don't line up 1:1 with how they are stored
+    VALID_KEYS = [
+       'hosts', 'name', 'vars', 'vars_prompt', 'vars_files',
+       'tasks', 'handlers', 'user', 'port', 'include',
+       'sudo', 'sudo_user', 'connection', 'tags', 'gather_facts'
+    ]
+
     # *************************************************
 
     def __init__(self, playbook, ds):
         ''' constructor loads from a play datastructure '''
 
+        for x in ds.keys():
+             if not x in Play.VALID_KEYS:
+                 raise errors.AnsibleError("%s is not a legal parameter in an Ansible Playbook" % x)
+
         # TODO: more error handling
 
         hosts = ds.get('hosts')
diff --git a/lib/ansible/playbook/task.py b/lib/ansible/playbook/task.py
index 378ab103f3e..1a8323fa941 100644
--- a/lib/ansible/playbook/task.py
+++ b/lib/ansible/playbook/task.py
@@ -26,9 +26,19 @@ class Task(object):
         'play', 'notified_by', 'tags', 'with_items', 'first_available_file'
     ]
 
+    # to prevent typos and such
+    VALID_KEYS = [
+         'name', 'action', 'only_if', 'async', 'poll', 'notify', 'with_items', 'first_available_file',
+         'include', 'tags'
+    ]
+
     def __init__(self, play, ds, module_vars=None):
         ''' constructor loads from a task or handler datastructure '''
 
+        for x in ds.keys():
+            if not x in Task.VALID_KEYS:
+                raise errors.AnsibleError("%s is not a legal parameter in an Ansible task or handler" % x)
+
         self.module_vars = module_vars
         self.play        = play