diff --git a/src/upgrades/4.0.0/regenerate_slugs_for_users_with_periods.js b/src/upgrades/4.0.0/regenerate_slugs_for_users_with_periods.js
new file mode 100644
index 0000000000..8b516e1883
--- /dev/null
+++ b/src/upgrades/4.0.0/regenerate_slugs_for_users_with_periods.js
@@ -0,0 +1,33 @@
+'use strict';
+
+const db = require('../../database');
+const batch = require('../../batch');
+const user = require('../../user');
+const slugify = require('../../slugify');
+
+module.exports = {
+	name: 'Regenerate user slugs for users whose usernames contained periods',
+	timestamp: Date.UTC(2024, 10, 28),
+	method: async function () {
+		const { progress } = this;
+
+		await batch.processSortedSet('users:joindate', async (uids) => {
+			const data = await user.getUsersFields(uids, ['username', 'userslug']);
+			await Promise.all(data.map(async ({ uid, username, userslug }) => {
+				if (username.includes('.') && userslug !== slugify(username)) {
+					const value = slugify(username);
+					await Promise.all([
+						db.sortedSetRemove('userslug:uid', userslug),
+						user.setUserField(uid, 'userslug', value),
+						db.sortedSetAdd('userslug:uid', uid, value),
+					]);
+				}
+			}));
+
+			progress.incr(uids.length);
+		}, {
+			batch: 500,
+			progress: progress,
+		});
+	},
+};