diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index a44094cdbc36..f020d5594154 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -408,14 +408,14 @@ static int mei_hbm_add_cl_resp(struct mei_device *dev, u8 addr, u8 status)
 {
 	struct mei_msg_hdr mei_hdr;
 	struct hbm_add_client_response resp;
-	const size_t len = sizeof(struct hbm_add_client_response);
+	const size_t len = sizeof(resp);
 	int ret;
 
 	dev_dbg(dev->dev, "adding client response\n");
 
 	mei_hbm_hdr(&mei_hdr, len);
 
-	memset(&resp, 0, sizeof(struct hbm_add_client_response));
+	memset(&resp, 0, len);
 	resp.hbm_cmd = MEI_HBM_ADD_CLIENT_RES_CMD;
 	resp.me_addr = addr;
 	resp.status  = status;
diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h
index b1a8d5ec88b3..8c0297f0e7f3 100644
--- a/drivers/misc/mei/hw.h
+++ b/drivers/misc/mei/hw.h
@@ -346,13 +346,13 @@ struct hbm_add_client_request {
  * @hbm_cmd: bus message command header
  * @me_addr: address of the client in ME
  * @status: if HBMS_SUCCESS then the client can now accept connections.
- * @reserved: reserved
+ * @reserved: reserved for alignment.
  */
 struct hbm_add_client_response {
 	u8 hbm_cmd;
 	u8 me_addr;
 	u8 status;
-	u8 reserved[1];
+	u8 reserved;
 } __packed;
 
 /**
@@ -461,7 +461,7 @@ struct hbm_notification {
 	u8 hbm_cmd;
 	u8 me_addr;
 	u8 host_addr;
-	u8 reserved[1];
+	u8 reserved;
 } __packed;
 
 /**