diff --git a/doc/REST-CalDAV-CardDAV/Timesheet.md b/doc/REST-CalDAV-CardDAV/Timesheet.md
index 2bd42c7e1f..b777e9ba62 100644
--- a/doc/REST-CalDAV-CardDAV/Timesheet.md
+++ b/doc/REST-CalDAV-CardDAV/Timesheet.md
@@ -14,6 +14,7 @@ Following schema is used for JSON encoding of timesheets
 * duration: integer in minutes
 * quantity: double
 * project: string
+* pm_id: integer ID of ProjectManager app (readonly currently!)
 * unitprice: double
 * category: category object with a single(!) category-name e.g. `{"category name": true}`
 * owner: string with either email or username or integer ID
@@ -188,6 +189,7 @@ curl 'https://example.org/egroupware/groupdav.php/timesheet/140' -H "Accept: app
     "duration": 60,
     "quantity": 1,
     "project": "2024-0001: Test Project",
+    "pm_id": 123,
     "unitprice": 100.0,
     "pricelist": 123,
     "owner": "ralf@example.org",
diff --git a/timesheet/src/JsTimesheet.php b/timesheet/src/JsTimesheet.php
index 212195056e..702f357536 100644
--- a/timesheet/src/JsTimesheet.php
+++ b/timesheet/src/JsTimesheet.php
@@ -52,7 +52,8 @@ class JsTimesheet extends Api\CalDAV\JsBase
 			'description' => $timesheet['description'],
 			'start' => self::UTCDateTime($timesheet['start'], true),
 			'duration' => (int)$timesheet['duration'],
-			'project' => $timesheet['project'],
+			'project' => $timesheet['project_blur'] ?? null,
+			'pm_id' => !empty($timesheet['pm_id']) ? (int)$timesheet['pm_id'] : null,
 			'quantity' => (double)$timesheet['quantity'],
 			'unitprice' => (double)$timesheet['unitprice'],
 			'category' => self::categories($timesheet['cat_id']),