diff --git a/changelog.d/3447.misc b/changelog.d/3447.misc
new file mode 100644
index 000000000..e69de29bb
diff --git a/synapse/util/caches/stream_change_cache.py b/synapse/util/caches/stream_change_cache.py
index c81518c6b..b19feb3b1 100644
--- a/synapse/util/caches/stream_change_cache.py
+++ b/synapse/util/caches/stream_change_cache.py
@@ -78,7 +78,7 @@ class StreamChangeCache(object):
             not_known_entities = set(entities) - set(self._entity_to_key)
 
             result = (
-                {self._cache[k] for k in in self._cache.islice(
+                {self._cache[k] for k in self._cache.islice(
                     start=self._cache.bisect_right(stream_pos))}
                 .intersection(entities)
                 .union(not_known_entities)
@@ -114,7 +114,7 @@ class StreamChangeCache(object):
         assert type(stream_pos) is int
 
         if stream_pos >= self._earliest_known_stream_pos:
-            return {self._cache[k] for k in in self._cache.islice(
+            return {self._cache[k] for k in self._cache.islice(
                 start=self._cache.bisect_right(stream_pos))}
         else:
             return None