diff --git a/changelog.d/8447.bugfix b/changelog.d/8447.bugfix
new file mode 100644
index 0000000000..88edaf322e
--- /dev/null
+++ b/changelog.d/8447.bugfix
@@ -0,0 +1 @@
+Fix DB query on startup for negative streams which caused long start up times. Introduced in #8374.
diff --git a/synapse/storage/util/id_generators.py b/synapse/storage/util/id_generators.py
index 02fbb656e8..48efbb5067 100644
--- a/synapse/storage/util/id_generators.py
+++ b/synapse/storage/util/id_generators.py
@@ -341,7 +341,7 @@ class MultiWriterIdGenerator:
                 "cmp": "<=" if self._positive else ">=",
             }
             sql = self._db.engine.convert_param_style(sql)
-            cur.execute(sql, (min_stream_id,))
+            cur.execute(sql, (min_stream_id * self._return_factor,))
 
             self._persisted_upto_position = min_stream_id