diff --git a/api-reference/beta/api/plannertask-update.md b/api-reference/beta/api/plannertask-update.md
index 4359be59e55..56f259189b6 100644
--- a/api-reference/beta/api/plannertask-update.md
+++ b/api-reference/beta/api/plannertask-update.md
@@ -55,6 +55,9 @@ PATCH /planner/tasks/{id}
 |startDateTime|DateTimeOffset|Date and time at which the task starts. The Timestamp type represents date and time information using ISO 8601 format and is always in UTC time. For example, midnight UTC on Jan 1, 2014 is `2014-01-01T00:00:00Z`.|
 |title|String|Title of the task.|
 
+> [!NOTE]
+> For Project tasks that are replicated to Planner, only the **percentComplete** property can be updated.
+
 ## Response
 
 If successful, this method returns a `204 No Content` response code and an empty content. If the request specifies the `Prefer` header with a `return=representation` preference, then this method returns a `200 OK` response code and an updated [plannerTask](../resources/plannertask.md) object in the response body.
diff --git a/api-reference/v1.0/api/plannertask-update.md b/api-reference/v1.0/api/plannertask-update.md
index ed2bdde395d..bcb86e0676d 100644
--- a/api-reference/v1.0/api/plannertask-update.md
+++ b/api-reference/v1.0/api/plannertask-update.md
@@ -54,6 +54,9 @@ PATCH /planner/tasks/{id}
 |startDateTime|DateTimeOffset|Date and time at which the task starts. The Timestamp type represents date and time information using ISO 8601 format and is always in UTC time. For example, midnight UTC on Jan 1, 2014 is `2014-01-01T00:00:00Z`.|
 |title|String|Title of the task.|
 
+> [!NOTE]
+> For Project tasks that are replicated to Planner, only the **percentComplete** property can be updated.
+
 ## Response
 
 If successful, this method returns a `204 No Content` response code and an empty content. If the request specifies the `Prefer` header with a `return=representation` preference, then this method returns a `200 OK` response code and an updated [plannerTask](../resources/plannertask.md) object in the response body.