diff --git a/packages/backend/migration/1748990662839-fix-IDX_instance_host_key.js b/packages/backend/migration/1748990662839-fix-IDX_instance_host_key.js
new file mode 100644
index 0000000000..fc6d303743
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+++ b/packages/backend/migration/1748990662839-fix-IDX_instance_host_key.js
@@ -0,0 +1,22 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export class FixIDXInstanceHostKey1748990662839 {
+	async up(queryRunner) {
+		// must include host for index-only scans: https://www.postgresql.org/docs/current/indexes-index-only-scans.html
+		await queryRunner.query(`DROP INDEX "public"."IDX_instance_host_key"`);
+		await queryRunner.query(`
+			create index "IDX_instance_host_key"
+			on "instance" ((lower(reverse("host"::text)) || '.'::text) text_pattern_ops)
+			include ("host")
+		`);
+		await queryRunner.query(`comment on index "IDX_instance_host_key" is 'Expression index for finding instances by base domain'`);
+	}
+
+	async down(queryRunner) {
+		await queryRunner.query(`DROP INDEX "public"."IDX_instance_host_key"`);
+		await queryRunner.query(`CREATE UNIQUE INDEX "IDX_instance_host_key" ON "instance" (((lower(reverse("host")) || '.')::text) text_pattern_ops)`);
+	}
+}