diff --git a/ble/att.h b/ble/att.h
index d488b5e70..1f99d51e1 100644
--- a/ble/att.h
+++ b/ble/att.h
@@ -105,8 +105,8 @@ extern "C" {
 #define ATT_ERROR_UNSUPPORTED_GROUP_TYPE           0x10
 #define ATT_ERROR_INSUFFICIENT_RESOURCES           0x11
 // custom BTstack ATT error coders
-#define ATT_ERROR_DATA_MISMATCH                    0x7e
 #define ATT_ERROR_TIMEOUT                          0x7F
+
     
 // custom BTstack error codes
 #define ATT_ERROR_HCI_DISCONNECT_RECEIVED          0x1f
@@ -161,7 +161,6 @@ extern "C" {
 #define GAP_APPEARANCE_UUID            0x2a01
 #define GAP_PERIPHERAL_PRIVACY_FLAG    0x2a02
 #define GAP_RECONNECTION_ADDRESS_UUID  0x2a03
-#define GAP_PERIPHERAL_PREFERRED_CONNECTION_PARAMETERS_UUID 0x2a04
 
 
 typedef struct att_connection {