diff --git a/kestrel/src/ipmi_bt.h b/kestrel/src/ipmi_bt.h
index 6a7aee7ab0c150b74b0b356b763adfb9a771ebc9..91ff9ffb835b10678d82cfad64f46854d173cedf 100644
--- a/kestrel/src/ipmi_bt.h
+++ b/kestrel/src/ipmi_bt.h
@@ -174,7 +174,7 @@ typedef struct __attribute__((packed)) ipmi_request_message
     uint8_t netfn_lun;
     uint8_t sequence;
     uint8_t command;
-    uint8_t data[256 - BASE_IPMI_REQUEST_LENGTH];
+    uint8_t data[256 - (BASE_IPMI_REQUEST_LENGTH + 1)];
 } ipmi_request_message_t;
 
 typedef struct __attribute__((packed)) ipmi_response_message
@@ -184,7 +184,7 @@ typedef struct __attribute__((packed)) ipmi_response_message
     uint8_t sequence;
     uint8_t command;
     uint8_t completion_code;
-    uint8_t data[256 - BASE_IPMI_REQUEST_LENGTH];
+    uint8_t data[256 - (BASE_IPMI_RESPONSE_LENGTH + 1)];
 } ipmi_response_message_t;
 
 /* All fields a little endian encoded. However the cputole* and le*tocpu