diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index cab5cadca8ef..5203977ed35d 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -470,6 +470,7 @@ struct tee_ioctl_object_invoke_arg {
 	__u32 op;
 	__u32 ret;
 	__u32 num_params;
+	__u32 :32;
 	/* num_params tells the actual number of element in params */
 	struct tee_ioctl_param params[];
 };