diff --git a/src/drivers/pwm_out_rc_in/CMakeLists.txt b/src/drivers/pwm_out_rc_in/CMakeLists.txt
index 08764c7f05..24faeff27f 100644
--- a/src/drivers/pwm_out_rc_in/CMakeLists.txt
+++ b/src/drivers/pwm_out_rc_in/CMakeLists.txt
@@ -35,6 +35,7 @@ px4_add_module(
 	MAIN pwm_out_rc_in
 	COMPILE_FLAGS
 		-Os
+		-DMAVLINK_COMM_NUM_BUFFERS=1
 	SRCS
 		pwm_out_rc_in.cpp
 	DEPENDS