diff --git a/google/cloud/aiplatform/v1beta1/custom_job.proto b/google/cloud/aiplatform/v1beta1/custom_job.proto
index 405dd8480c..5ad6c69f4b 100644
--- a/google/cloud/aiplatform/v1beta1/custom_job.proto
+++ b/google/cloud/aiplatform/v1beta1/custom_job.proto
@@ -394,4 +394,11 @@ message Scheduling {
   // job starts running. If true, overrides
   // `Scheduling.restart_job_on_worker_restart` to false.
   bool disable_retries = 5 [(google.api.field_behavior) = OPTIONAL];
+
+  // Optional. This is the maximum duration that a job will wait for the
+  // requested resources to be provisioned if the scheduling strategy is set to
+  // [Strategy.DWS_FLEX_START].
+  // If set to 0, the job will wait indefinitely. The default is 24 hours.
+  google.protobuf.Duration max_wait_duration = 6
+      [(google.api.field_behavior) = OPTIONAL];
 }