diff --git a/site/gatsby-site/migrations/2025.09.25T15.00.48.incidents-remove-epoch-date-modified.js b/site/gatsby-site/migrations/2025.09.25T15.00.48.incidents-remove-epoch-date-modified.js
new file mode 100644
index 0000000000..6ee0a11b46
--- /dev/null
+++ b/site/gatsby-site/migrations/2025.09.25T15.00.48.incidents-remove-epoch-date-modified.js
@@ -0,0 +1,14 @@
+/** @type {import('umzug').MigrationFn<any>} */
+exports.up = async ({ context: { client } }) => {
+  const db = client.db('aiidprod');
+
+  const incidentsCollection = db.collection('incidents');
+
+  // Remove the old epoch_date_modified field
+  const removeResult = await incidentsCollection.updateMany(
+    { epoch_date_modified: { $exists: true } },
+    { $unset: { epoch_date_modified: '' } }
+  );
+
+  console.log(`Removed epoch_date_modified field from ${removeResult.modifiedCount} incidents.`);
+};