diff --git a/boards/controllino_maxi.json b/boards/controllino_maxi.json
index a344baa..457c587 100644
--- a/boards/controllino_maxi.json
+++ b/boards/controllino_maxi.json
@@ -1,7 +1,7 @@
 {
   "build": {
     "core": "arduino",
-    "extra_flags": "-DARDUINO_AVR_MEGA2560",
+    "extra_flags": "-DARDUINO_AVR_MEGA2560 -DRS485_SERIAL_PORT=Serial3 -DRS485_DEFAULT_TX_PIN=14 -DCUSTOM_RS485_DEFAULT_DE_PIN=75 -DCUSTOM_RS485_DEFAULT_RE_PIN=76",
     "f_cpu": "16000000L",
     "hwids": [
       [
diff --git a/boards/controllino_mega.json b/boards/controllino_mega.json
index 119f7ec..5c1848d 100644
--- a/boards/controllino_mega.json
+++ b/boards/controllino_mega.json
@@ -1,7 +1,7 @@
 {
   "build": {
     "core": "arduino",
-    "extra_flags": "-DARDUINO_AVR_MEGA2560",
+    "extra_flags": "-DARDUINO_AVR_MEGA2560 -DRS485_SERIAL_PORT=Serial3 -DRS485_DEFAULT_TX_PIN=14 -DCUSTOM_RS485_DEFAULT_DE_PIN=75 -DCUSTOM_RS485_DEFAULT_RE_PIN=76",
     "f_cpu": "16000000L",
     "hwids": [
       [