diff --git a/apps/server/src/classes/data-provider/DataProvider.ts b/apps/server/src/classes/data-provider/DataProvider.ts
index 35d781d64..66321b7e4 100644
--- a/apps/server/src/classes/data-provider/DataProvider.ts
+++ b/apps/server/src/classes/data-provider/DataProvider.ts
@@ -12,7 +12,6 @@ import {
   ViewSettings,
 } from 'ontime-types';
 
-import { cloneRundown } from '../../api-data/rundown/rundown.utils.js';
 import { isTest } from '../../setup/environment.js';
 import { shouldCrashDev } from '../../utils/development.js';
 import { isPath } from '../../utils/fileManagement.js';
@@ -102,8 +101,16 @@ function getCustomFields(): Readonly<CustomFields> {
   return db.data.customFields;
 }
 
+/**
+ * Stores a rundown, replacing any existing entry for the same key.
+ * Takes ownership of `newData` and stores it by reference - the caller must not mutate it
+ * afterward. Every call site either hands over a freshly-built object it never touches again,
+ * or (for the loaded rundown) the cache's own long-lived object, which is already the single
+ * source of truth for that data - aliasing it here costs nothing and avoids a second full
+ * deep copy of the rundown on every commit.
+ */
 async function setRundown(rundownKey: string, newData: Rundown): ReadonlyPromise<ProjectRundowns> {
-  db.data.rundowns[rundownKey] = cloneRundown(newData);
+  db.data.rundowns[rundownKey] = newData;
   await persist();
   return db.data.rundowns;
 }