diff --git a/enterprise/v2/posture/posture.proto b/enterprise/v2/posture/posture.proto
index fa4022c..32ceb06 100644
--- a/enterprise/v2/posture/posture.proto
+++ b/enterprise/v2/posture/posture.proto
@@ -60,6 +60,8 @@ message DevicePostureCheckRequest {
   int64 location_id = 1;
   string pubkey = 2;
   DevicePostureData device_posture_data = 3;
+  // Polling token of the calling device, used to authenticate the request.
+  optional string token = 4;
 }
 
 message DevicePostureCheckResponse {