3 files changed, 10 insertions, 0 deletions
diff --git a/lib/sqlalchemy/event/attr.py b/lib/sqlalchemy/event/attr.py
index be2a82208..5e3499209 100644
--- a/lib/sqlalchemy/event/attr.py
+++ b/lib/sqlalchemy/event/attr.py
@@ -340,6 +340,8 @@ class _ListenerCollection(RefCollection, _CompoundListener):
 
 
 class _JoinedDispatchDescriptor(object):
+    __slots__ = 'name',
+
     def __init__(self, name):
         self.name = name
 
@@ -357,6 +359,8 @@ class _JoinedDispatchDescriptor(object):
 class _JoinedListener(_CompoundListener):
     _exec_once = False
 
+    __slots__ = 'parent', 'name', 'local', 'parent_listeners'
+
     def __init__(self, parent, name, local):
         self.parent = parent
         self.name = name
diff --git a/lib/sqlalchemy/event/base.py b/lib/sqlalchemy/event/base.py
index 4925f6ffa..37bd2c49e 100644
--- a/lib/sqlalchemy/event/base.py
+++ b/lib/sqlalchemy/event/base.py
@@ -195,6 +195,8 @@ class Events(util.with_metaclass(_EventMeta, object)):
 class _JoinedDispatcher(object):
     """Represent a connection between two _Dispatch objects."""
 
+    __slots__ = 'local', 'parent', '_parent_cls'
+
     def __init__(self, local, parent):
         self.local = local
         self.parent = parent
diff --git a/lib/sqlalchemy/event/registry.py b/lib/sqlalchemy/event/registry.py
index 5b422c401..fc26f91d7 100644
--- a/lib/sqlalchemy/event/registry.py
+++ b/lib/sqlalchemy/event/registry.py
@@ -140,6 +140,10 @@ class _EventKey(object):
     """Represent :func:`.listen` arguments.
     """
 
+    __slots__ = (
+        'target', 'identifier', 'fn', 'fn_key', 'fn_wrap', 'dispatch_target'
+    )
+
     def __init__(self, target, identifier,
                  fn, dispatch_target, _fn_wrap=None):
         self.target = target