diff --git a/pkg/kubelet/api/v1alpha1/runtime/api.proto b/pkg/kubelet/api/v1alpha1/runtime/api.proto
index a680b0bffd..2caa1d5b74 100644
--- a/pkg/kubelet/api/v1alpha1/runtime/api.proto
+++ b/pkg/kubelet/api/v1alpha1/runtime/api.proto
@@ -607,7 +607,7 @@ message ExecRequest {
     // Whether use tty
     optional bool tty = 3;
     // Streaming stdin
-    optional bytes stdin = 4;
+    optional bool stdin = 4;
 }
 
 message ExecResponse {
@@ -619,7 +619,7 @@ message AttachRequest {
     // The id of the container
     optional string container_id = 1;
     // Streaming stdin
-    optional bytes stdin = 2;
+    optional string stdin = 2;
 }
 
 message AttachResponse {