diff --git a/WifiInterface.cpp b/WifiInterface.cpp
index 8b2251a..87d5437 100644
--- a/WifiInterface.cpp
+++ b/WifiInterface.cpp
@@ -68,7 +68,9 @@ Stream * WifiInterface::wifiStream;
 #define NUM_SERIAL 3
 #define SERIAL1 Serial3
 #define SERIAL3 Serial5
-#elif defined(ARDUINO_NUCLEO_F413ZH) || defined(ARDUINO_NUCLEO_F429ZI) || defined(ARDUINO_NUCLEO_F446ZE) || defined(ARDUINO_NUCLEO_F412ZG)
+#elif defined(ARDUINO_NUCLEO_F413ZH) || defined(ARDUINO_NUCLEO_F429ZI) \
+    || defined(ARDUINO_NUCLEO_F446ZE) || defined(ARDUINO_NUCLEO_F412ZG) \
+    || defined(ARDUINO_NUCLEO_F439ZI)
 #define NUM_SERIAL 2
 #define SERIAL1 Serial6
 #else