diff --git a/ble/att.h b/ble/att.h
index 1f99d51e1..b8f733819 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
diff --git a/ble/gatt_client.c b/ble/gatt_client.c
index 1e83d5d24..9039c3d32 100644
--- a/ble/gatt_client.c
+++ b/ble/gatt_client.c
@@ -1257,7 +1257,7 @@ static void gatt_client_att_packet_handler(uint8_t packet_type, uint16_t handle,
                     if (is_value_valid(peripheral, packet, size)){
                         emit_gatt_complete_event(peripheral, 0);
                     } else {
-                        emit_gatt_complete_event(peripheral, GATT_CLIENT_DATA_MISMATCH);
+                        emit_gatt_complete_event(peripheral, ATT_ERROR_DATA_MISMATCH);
                     }
                     break;
 
diff --git a/src/hci_cmds.h b/src/hci_cmds.h
index dc1ef7c02..68c903572 100644
--- a/src/hci_cmds.h
+++ b/src/hci_cmds.h
@@ -804,7 +804,6 @@ extern "C" {
 
 #define GATT_CLIENT_NOT_CONNECTED                          0x93
 #define GATT_CLIENT_BUSY                                   0x94
-#define GATT_CLIENT_DATA_MISMATCH                          0x95
 
 #define BNEP_SERVICE_ALREADY_REGISTERED                    0xA0
 #define BNEP_CHANNEL_NOT_CONNECTED                         0xA1