diff --git a/changelog.d/14692.misc b/changelog.d/14692.misc
new file mode 100644
index 0000000000..0edac253b7
--- /dev/null
+++ b/changelog.d/14692.misc
@@ -0,0 +1 @@
+Check that the SQLite database file exists before porting to PostgreSQL.
\ No newline at end of file
diff --git a/synapse/_scripts/synapse_port_db.py b/synapse/_scripts/synapse_port_db.py
index d850e54e17..c463b60b26 100755
--- a/synapse/_scripts/synapse_port_db.py
+++ b/synapse/_scripts/synapse_port_db.py
@@ -1307,7 +1307,7 @@ def main() -> None:
     sqlite_config = {
         "name": "sqlite3",
         "args": {
-            "database": args.sqlite_database,
+            "database": "file:{}?mode=rw".format(args.sqlite_database),
             "cp_min": 1,
             "cp_max": 1,
             "check_same_thread": False,