diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 258b25114..e0d709869 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -455,7 +455,7 @@ class SQLBaseStore(object):
             insertion_values (dict): key/values to use when inserting
         Returns:
             Deferred(bool): True if a new entry was created, False if an
-                exisitng one was updated.
+                existing one was updated.
         """
         return self.runInteraction(
             desc,