diff --git a/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1/api.pb.go b/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1/api.pb.go
index 7d26cedf754..10c25f7a526 100644
--- a/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1/api.pb.go
+++ b/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1/api.pb.go
@@ -5665,6 +5665,7 @@ type ContainerStatus struct {
 	// image ID
 	ImageRef string `protobuf:"bytes,9,opt,name=image_ref,json=imageRef,proto3" json:"image_ref,omitempty"`
 	// Brief CamelCase string explaining why container is in its current state.
+	// Must be set to "OOMKilled" for containers terminated by cgroup-based Out-of-Memory killer.
 	Reason string `protobuf:"bytes,10,opt,name=reason,proto3" json:"reason,omitempty"`
 	// Human-readable message indicating details about why container is in its
 	// current state.
diff --git a/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1/api.proto b/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1/api.proto
index 3ed65775644..c744b6e12e3 100644
--- a/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1/api.proto
+++ b/staging/src/k8s.io/cri-api/pkg/apis/runtime/v1/api.proto
@@ -1211,6 +1211,7 @@ message ContainerStatus {
     // image ID
     string image_ref = 9;
     // Brief CamelCase string explaining why container is in its current state.
+    // Must be set to "OOMKilled" for containers terminated by cgroup-based Out-of-Memory killer.
     string reason = 10;
     // Human-readable message indicating details about why container is in its
     // current state.