diff --git a/plugins/Fediverse/plugin.py b/plugins/Fediverse/plugin.py
index 2bfcfa583..a438cf189 100644
--- a/plugins/Fediverse/plugin.py
+++ b/plugins/Fediverse/plugin.py
@@ -122,7 +122,7 @@ class Fediverse(callbacks.PluginRegexp):
     def __init__(self, irc):
         super().__init__(irc)
         self._startHttp()
-        self._actor_cache = utils.structures.ExpiringDict(timeout=600)
+        self._actor_cache = utils.structures.TimeoutDict(timeout=600)
 
     def _startHttp(self):
         callback = FediverseHttp()
diff --git a/src/irclib.py b/src/irclib.py
index f12b23d33..69a160b75 100644
--- a/src/irclib.py
+++ b/src/irclib.py
@@ -58,7 +58,7 @@ from . import conf, ircdb, ircmsgs, ircutils, log, utils, world
 from .drivers import Server
 from .utils.str import rsplit
 from .utils.iter import chain
-from .utils.structures import smallqueue, RingBuffer, TimeoutDict
+from .utils.structures import smallqueue, RingBuffer, ExpiringDict
 
 MAX_LINE_SIZE = 512 # Including \r\n, but excluding server_tags
 
@@ -557,7 +557,7 @@ class IrcState(IrcCommandDispatcher, log.Firewalled):
 
         # Batches should always finish and be way shorter than 3600s, but
         # let's just make sure to avoid leaking memory.
-        self.batches = TimeoutDict(timeout=3600)
+        self.batches = ExpiringDict(timeout=3600)
 
     def reset(self):
         """Resets the state to normal, unconnected state."""
diff --git a/src/utils/structures.py b/src/utils/structures.py
index 31c810355..63d1e3c91 100644
--- a/src/utils/structures.py
+++ b/src/utils/structures.py
@@ -307,6 +307,8 @@ class smallqueue(list):
 
 
 class TimeoutQueue(object):
+    """A queue whose elements are dropped after a certain time."""
+
     __slots__ = ('queue', 'timeout')
     def __init__(self, timeout, queue=None):
         if queue is None:
@@ -458,9 +460,9 @@ class CacheDict(collections.abc.MutableMapping):
         return len(self.d)
 
 
-class TimeoutDict(collections.abc.MutableMapping):
+class ExpiringDict(collections.abc.MutableMapping):
     """An efficient dictionary that MAY drop its items when they are too old.
-    For guaranteed expiry, use ExpiringDict.
+    For guaranteed expiry, use TimeoutDict.
 
     Currently, this is implemented by internally alternating two "generation"
     dicts, which are dropped after a certain time."""
@@ -478,7 +480,7 @@ class TimeoutDict(collections.abc.MutableMapping):
         return (self.__class__, (self.timeout, dict(self)))
 
     def __repr__(self):
-        return 'TimeoutDict(%s, %r)' % (self.timeout, dict(self))
+        return 'ExpiringDict(%s, %r)' % (self.timeout, dict(self))
 
     def __getitem__(self, key):
         try:
@@ -534,11 +536,11 @@ class TimeoutDict(collections.abc.MutableMapping):
         return len(set(self.new_gen.keys()) | set(self.old_gen.keys()))
 
 
-class ExpiringDict: # Don't inherit from MutableMapping: not thread-safe
+class TimeoutDict: # Don't inherit from MutableMapping: not thread-safe
     """A dictionary that drops its items after they have been in the dict
     for a certain time.
 
-    Use TimeoutDict for a more efficient implementation that doesn't require
+    Use ExpiringDict for a more efficient implementation that doesn't require
     guaranteed timeout.
     """
     __slots__ = ('_lock', 'd', 'timeout')
@@ -554,7 +556,7 @@ class ExpiringDict: # Don't inherit from MutableMapping: not thread-safe
         return (self.__class__, (self.timeout, dict(self)))
 
     def __repr__(self):
-        return 'ExpiringDict(%s, %r)' % (self.timeout, dict(self))
+        return 'TimeoutDict(%s, %r)' % (self.timeout, dict(self))
 
     def __getitem__(self, key):
         with self._lock:
diff --git a/test/test_utils.py b/test/test_utils.py
index f4ba2c0a8..6fbae59e9 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -1166,16 +1166,16 @@ class TestCacheDict(SupyTestCase):
             self.assertTrue(i in d)
             self.assertTrue(d[i] == i)
 
-class TestTimeoutDict(SupyTestCase):
+class TestExpiringDict(SupyTestCase):
     def testInit(self):
-        d = TimeoutDict(10)
+        d = ExpiringDict(10)
         self.assertEqual(dict(d), {})
         d['foo'] = 'bar'
         d['baz'] = 'qux'
         self.assertEqual(dict(d), {'foo': 'bar', 'baz': 'qux'})
 
     def testExpire(self):
-        d = TimeoutDict(10)
+        d = ExpiringDict(10)
         self.assertEqual(dict(d), {})
         d['foo'] = 'bar'
         timeFastForward(11)
@@ -1189,8 +1189,8 @@ class TestTimeoutDict(SupyTestCase):
         self.assertEqual(dict(d), {'baz': 'qux', 'quux': 42})
 
     def testEquality(self):
-        d1 = TimeoutDict(10)
-        d2 = TimeoutDict(10)
+        d1 = ExpiringDict(10)
+        d2 = ExpiringDict(10)
         self.assertEqual(d1, d2)
 
         d1['foo'] = 'bar'
@@ -1208,16 +1208,16 @@ class TestTimeoutDict(SupyTestCase):
         self.assertEqual(d1, d2)
 
 
-class TestExpiringDict(SupyTestCase):
+class TestTimeoutDict(SupyTestCase):
     def testInit(self):
-        d = ExpiringDict(10)
+        d = TimeoutDict(10)
         self.assertEqual(dict(d), {})
         d['foo'] = 'bar'
         d['baz'] = 'qux'
         self.assertEqual(dict(d), {'foo': 'bar', 'baz': 'qux'})
 
     def testExpire(self):
-        d = ExpiringDict(10)
+        d = TimeoutDict(10)
         self.assertEqual(dict(d), {})
         d['foo'] = 'bar'
         timeFastForward(11)
@@ -1231,8 +1231,8 @@ class TestExpiringDict(SupyTestCase):
         self.assertEqual(dict(d), {'quux': 42})
 
     def testEquality(self):
-        d1 = ExpiringDict(10)
-        d2 = ExpiringDict(10)
+        d1 = TimeoutDict(10)
+        d2 = TimeoutDict(10)
         self.assertEqual(d1, d2)
 
         d1['foo'] = 'bar'