diff --git a/services/web/scripts/history/downgrade_project.js b/services/web/scripts/history/downgrade_project.js
new file mode 100644
index 0000000000..78ac906273
--- /dev/null
+++ b/services/web/scripts/history/downgrade_project.js
@@ -0,0 +1,79 @@
+const VERBOSE_LOGGING = process.env.VERBOSE_LOGGING === 'true'
+const DRY_RUN = process.env.DRY_RUN !== 'false'
+process.env.MONGO_SOCKET_TIMEOUT =
+  parseInt(process.env.MONGO_SOCKET_TIMEOUT, 10) || 3600000
+
+const PROJECT_ID = process.env.PROJECT_ID
+
+const { ReadPreference, ObjectId } = require('mongodb')
+const { db, waitForDb } = require('../../app/src/infrastructure/mongodb')
+const ProjectHistoryHandler = require('../../app/src/Features/Project/ProjectHistoryHandler')
+
+console.log({
+  DRY_RUN,
+  VERBOSE_LOGGING,
+  PROJECT_ID,
+})
+
+let INTERRUPT = false
+
+async function processProject(project) {
+  if (INTERRUPT) {
+    return
+  }
+  if (!shouldPreserveHistory(project)) {
+    console.log(
+      `project ${project._id} does not have preserveHistory:true, skipping`
+    )
+    return
+  }
+  if (!DRY_RUN) {
+    await ProjectHistoryHandler.promises.downgradeHistory(project._id)
+  }
+  if (VERBOSE_LOGGING) {
+    console.log(
+      `project ${project._id} converted and upgraded to full project history`
+    )
+  }
+}
+
+async function shouldPreserveHistory(project) {
+  return await db.projectHistoryMetaData.findOne(
+    {
+      $and: [
+        { project_id: { $eq: project._id } },
+        { preserveHistory: { $eq: true } },
+      ],
+    },
+    { readPreference: ReadPreference.SECONDARY }
+  )
+}
+
+async function main() {
+  if (PROJECT_ID) {
+    await waitForDb()
+    const project = await db.projects.findOne({ _id: ObjectId(PROJECT_ID) })
+    await processProject(project)
+  } else {
+    console.log('PROJECT_ID environment value is needed.')
+    process.exit(1)
+  }
+}
+
+// Upgrading history is not atomic, if we quit out mid-initialisation
+// then history could get into a broken state
+// Instead, skip any unprocessed projects and exit() at end of the batch.
+process.on('SIGINT', function () {
+  console.log('Caught SIGINT, waiting for in process upgrades to complete')
+  INTERRUPT = true
+})
+
+main()
+  .then(() => {
+    console.error('Done.')
+    process.exit(0)
+  })
+  .catch(error => {
+    console.error({ error })
+    process.exit(1)
+  })