diff --git a/server/db-schema-test.js b/server/db-schema-test.js
index bb231fa..fbbd7c0 100644
--- a/server/db-schema-test.js
+++ b/server/db-schema-test.js
@@ -227,7 +227,7 @@ const MIGRATIONS_SQL = {
       created_at           TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
       updated_at           TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now'))
     );
-    CREATE UNIQUE INDEX idx_calendar_sub_extid
+    CREATE UNIQUE INDEX IF NOT EXISTS idx_calendar_sub_extid
       ON calendar_events (subscription_id, external_calendar_id)
       WHERE subscription_id IS NOT NULL;
     CREATE INDEX IF NOT EXISTS idx_calendar_sub ON calendar_events(subscription_id);
diff --git a/server/db.js b/server/db.js
index 1a35893..8a5d903 100644
--- a/server/db.js
+++ b/server/db.js
@@ -470,7 +470,7 @@ const MIGRATIONS = [
       CREATE INDEX IF NOT EXISTS idx_calendar_external_id ON calendar_events(external_calendar_id);
       CREATE INDEX IF NOT EXISTS idx_calendar_sub         ON calendar_events(subscription_id);
 
-      CREATE UNIQUE INDEX idx_calendar_sub_extid
+      CREATE UNIQUE INDEX IF NOT EXISTS idx_calendar_sub_extid
         ON calendar_events (subscription_id, external_calendar_id)
         WHERE subscription_id IS NOT NULL;
     `,