diff --git a/lib/ansible/inventory/__init__.py b/lib/ansible/inventory/__init__.py
index 60a3523abaa..7c2212c5a02 100644
--- a/lib/ansible/inventory/__init__.py
+++ b/lib/ansible/inventory/__init__.py
@@ -35,6 +35,9 @@ class Inventory(object):
     Host inventory for ansible.
     """
 
+    __slots__ = [ 'host_list', 'groups', '_restriction', '_is_script',
+                  'parser' ] 
+
     def __init__(self, host_list=C.DEFAULT_HOST_LIST):
 
         # the host file file, or script path, or list of hosts
diff --git a/lib/ansible/inventory/group.py b/lib/ansible/inventory/group.py
index a51de0c89c5..9552f244c78 100644
--- a/lib/ansible/inventory/group.py
+++ b/lib/ansible/inventory/group.py
@@ -18,6 +18,8 @@
 class Group(object):
     ''' a group of ansible hosts '''
 
+    __slots__ = [ 'name', 'hosts', 'vars', 'child_groups', 'parent_groups' ]
+
     def __init__(self, name=None):
 
         self.name = name
diff --git a/lib/ansible/inventory/host.py b/lib/ansible/inventory/host.py
index 0c43471801c..c96a5cb0ce8 100644
--- a/lib/ansible/inventory/host.py
+++ b/lib/ansible/inventory/host.py
@@ -21,6 +21,8 @@ import ansible.constants as C
 class Host(object):
     ''' a single ansible host '''
 
+    __slots__ = [ 'name', 'vars', 'groups' ]
+
     def __init__(self, name=None, port=None):
 
         self.name = name
diff --git a/lib/ansible/inventory/yaml.py b/lib/ansible/inventory/yaml.py
index afeaa401395..f17aa723136 100644
--- a/lib/ansible/inventory/yaml.py
+++ b/lib/ansible/inventory/yaml.py
@@ -25,6 +25,8 @@ import sys
 class InventoryParserYaml(object):
     ''' Host inventory parser for ansible '''
 
+    __slots__ = [ '_hosts', 'groups' ]
+
     def __init__(self, filename=C.DEFAULT_HOST_LIST):
 
         sys.stderr.write("WARNING: YAML inventory files are deprecated in 0.6 and will be removed in 0.7, to migrate" +