diff --git a/boards/px4/fmu-v2/default.cmake b/boards/px4/fmu-v2/default.cmake
index 5560f41d6feb04166709525fa61dca0e6d7bf8ce..02563e8b5a7bfc6bdb45fc5e3c434afa6dd62995 100644
--- a/boards/px4/fmu-v2/default.cmake
+++ b/boards/px4/fmu-v2/default.cmake
@@ -13,10 +13,10 @@ px4_add_board(
 	#UAVCAN_INTERFACES 2
 
 	SERIAL_PORTS
-		GPS1:/dev/ttyS0
+		GPS1:/dev/ttyS3
 		TEL1:/dev/ttyS1
 		TEL2:/dev/ttyS2
-		TEL4:/dev/ttyS3
+		TEL4:/dev/ttyS6
 
 	DRIVERS
 		#barometer # all available barometer drivers
diff --git a/boards/px4/fmu-v3/default.cmake b/boards/px4/fmu-v3/default.cmake
index c19349fc67c79d2251238446ca311d14afded712..165851519915055aea3bcf890c7cf4b07501410f 100644
--- a/boards/px4/fmu-v3/default.cmake
+++ b/boards/px4/fmu-v3/default.cmake
@@ -14,10 +14,10 @@ px4_add_board(
 	UAVCAN_INTERFACES 2
 
 	SERIAL_PORTS
-		GPS1:/dev/ttyS0
+		GPS1:/dev/ttyS3
 		TEL1:/dev/ttyS1
 		TEL2:/dev/ttyS2
-		TEL4:/dev/ttyS3
+		TEL4:/dev/ttyS6
 
 	DRIVERS
 		barometer # all available barometer drivers