diff --git a/changelog.d/19155.bugfix b/changelog.d/19155.bugfix
new file mode 100644
index 000000000..825596b9d
--- /dev/null
+++ b/changelog.d/19155.bugfix
@@ -0,0 +1 @@
+Let the SQLite-to-PostgreSQL migration script correctly migrate a boolean column in the `delayed_events` table.
diff --git a/synapse/_scripts/synapse_port_db.py b/synapse/_scripts/synapse_port_db.py
index 1806e42d9..7e3117b8d 100755
--- a/synapse/_scripts/synapse_port_db.py
+++ b/synapse/_scripts/synapse_port_db.py
@@ -107,6 +107,7 @@ logger = logging.getLogger("synapse_port_db")
 BOOLEAN_COLUMNS = {
     "access_tokens": ["used"],
     "account_validity": ["email_sent"],
+    "delayed_events": ["is_processed"],
     "device_lists_changes_in_room": ["converted_to_destinations"],
     "device_lists_outbound_pokes": ["sent"],
     "devices": ["hidden"],