diff --git a/slixmpp/plugins/xep_0313/mam.py b/slixmpp/plugins/xep_0313/mam.py
index e3268e9b..d407e2bf 100644
--- a/slixmpp/plugins/xep_0313/mam.py
+++ b/slixmpp/plugins/xep_0313/mam.py
@@ -8,9 +8,11 @@
 
 import logging
 
-import slixmpp
+from datetime import datetime
+from typing import Any, Dict, Callable, Optional, Awaitable
+
+from slixmpp import JID
 from slixmpp.stanza import Message, Iq
-from slixmpp.exceptions import XMPPError
 from slixmpp.xmlstream.handler import Collector
 from slixmpp.xmlstream.matcher import StanzaPath
 from slixmpp.xmlstream import register_stanza_plugin
@@ -41,8 +43,32 @@ class XEP_0313(BasePlugin):
         register_stanza_plugin(stanza.MAM, self.xmpp['xep_0059'].stanza.Set)
         register_stanza_plugin(stanza.Fin, self.xmpp['xep_0059'].stanza.Set)
 
-    def retrieve(self, jid=None, start=None, end=None, with_jid=None, ifrom=None,
-                 reverse=False, timeout=None, callback=None, iterator=False, rsm=None):
+    def retrieve(
+            self,
+            jid: Optional[JID] = None,
+            start: Optional[datetime] = None,
+            end: Optional[datetime] = None,
+            with_jid: Optional[JID] = None,
+            ifrom: Optional[JID] = None,
+            reverse: bool = False,
+            timeout: int = None,
+            callback: Callable[[Iq], None] = None,
+            iterator: bool = False,
+            rsm: Optional[Dict[str, Any]] = None
+    ) -> Awaitable:
+        """
+        Send a MAM query and retrieve the results.
+
+        :param JID jid: Entity holding the MAM records
+        :param datetime start,end: MAM query temporal boundaries
+        :param JID with_jid: Filter results on this JID
+        :param JID ifrom: To change the from address of the query
+        :param bool reverse: Get the results in reverse order
+        :param int timeout: IQ timeout
+        :param func callback: Custom callback for handling results
+        :param bool iterator: Use RSM and iterate over a paginated query
+        :param dict rsm: RSM custom options
+        """
         iq = self.xmpp.Iq()
         query_id = iq['id']
 
@@ -57,11 +83,11 @@ class XEP_0313(BasePlugin):
         if rsm:
             for key, value in rsm.items():
                 iq['mam']['rsm'][key] = str(value)
-                if key is 'max':
+                if key == 'max':
                     amount = value
-
         cb_data = {}
-        def pre_cb(query):
+
+        def pre_cb(query: Iq) -> None:
             query['mam']['queryid'] = query['id']
             collector = Collector(
                 'MAM_Results_%s' % query_id,
@@ -69,7 +95,7 @@ class XEP_0313(BasePlugin):
             self.xmpp.register_handler(collector)
             cb_data['collector'] = collector
 
-        def post_cb(result):
+        def post_cb(result: Iq) -> None:
             results = cb_data['collector'].stop()
             if result['type'] == 'result':
                 result['mam']['results'] = results
@@ -84,7 +110,7 @@ class XEP_0313(BasePlugin):
             StanzaPath('message/mam_result@queryid=%s' % query_id))
         self.xmpp.register_handler(collector)
 
-        def wrapped_cb(iq):
+        def wrapped_cb(iq: Iq) -> None:
             results = collector.stop()
             if iq['type'] == 'result':
                 iq['mam']['results'] = results