diff --git a/mk/px4_targets.mk b/mk/px4_targets.mk
index 6a735fe957a462c5626cd86051d69e0496a8fa6a..857fc959781d24c4af68174b8f36f3fd6a85668d 100644
--- a/mk/px4_targets.mk
+++ b/mk/px4_targets.mk
@@ -45,7 +45,7 @@ PX4_V2_CONFIG_FILE=$(MK_DIR)/PX4/config_px4fmu-v2_APM.mk
 
 SKETCHFLAGS=$(SKETCHLIBINCLUDES) -I$(PWD) -DARDUPILOT_BUILD -DTESTS_MATHLIB_DISABLE -DCONFIG_HAL_BOARD=HAL_BOARD_PX4 -DSKETCHNAME="\\\"$(SKETCH)\\\"" -DSKETCH_MAIN=ArduPilot_main -DAPM_BUILD_DIRECTORY=APM_BUILD_$(SKETCH)
 
-WARNFLAGS = -Wno-psabi -Wno-packed -Wno-error=double-promotion -Wno-error=unused-variable -Wno-error=unused-but-set-variable -Wno-error=reorder -Wno-error=float-equal -Wno-error=frame-larger-than=1024 -Wno-error=pmf-conversions -Wno-error=missing-declarations
+WARNFLAGS = -Wno-psabi -Wno-packed -Wno-error=double-promotion -Wno-error=unused-variable -Wno-error=reorder -Wno-error=float-equal -Wno-error=pmf-conversions -Wno-error=missing-declarations -Wno-error=unused-function
 
 # avoid PX4 submodules
 export GIT_SUBMODULES_ARE_EVIL = 1