diff --git a/specification/ml/_types/TrainedModel.ts b/specification/ml/_types/TrainedModel.ts
index f95c975e66..3405b440f8 100644
--- a/specification/ml/_types/TrainedModel.ts
+++ b/specification/ml/_types/TrainedModel.ts
@@ -63,7 +63,7 @@ export class TrainedModelStats {
 export class TrainedModelDeploymentStats {
   adaptive_allocations?: AdaptiveAllocationsSettings
   /** The detailed allocation status for the deployment. */
-  allocation_status: TrainedModelDeploymentAllocationStatus
+  allocation_status?: TrainedModelDeploymentAllocationStatus
   cache_size?: ByteSize
   /** The unique identifier for the trained model deployment. */
   deployment_id: Id