diff --git a/changelog.d/4263.bugfix b/changelog.d/4263.bugfix
new file mode 100644
index 0000000000..3dc1d7c732
--- /dev/null
+++ b/changelog.d/4263.bugfix
@@ -0,0 +1 @@
+Prevent crash on pagination.
diff --git a/synapse/handlers/pagination.py b/synapse/handlers/pagination.py
index 9d257ecf31..084c1503da 100644
--- a/synapse/handlers/pagination.py
+++ b/synapse/handlers/pagination.py
@@ -254,7 +254,7 @@ class PaginationHandler(object):
             })
 
         state = None
-        if event_filter and event_filter.lazy_load_members():
+        if event_filter and event_filter.lazy_load_members() and len(events) > 0:
             # TODO: remove redundant members
 
             # FIXME: we also care about invite targets etc.