diff --git a/mk/PX4/config_px4fmu-v1_APM.mk b/mk/PX4/config_px4fmu-v1_APM.mk
index 8eeacb210f..6ea5253587 100644
--- a/mk/PX4/config_px4fmu-v1_APM.mk
+++ b/mk/PX4/config_px4fmu-v1_APM.mk
@@ -62,6 +62,7 @@ MODULES		+= modules/uORB
 MODULES		+= lib/mathlib/math/filter
 MODULES	        += modules/libtomfastmath
 MODULES         += modules/libtomcrypt
+MODULES		+= lib/conversion
 
 #
 # Transitional support - add commands from the NuttX export archive.
diff --git a/mk/PX4/config_px4fmu-v2_APM.mk b/mk/PX4/config_px4fmu-v2_APM.mk
index b186035b66..8c0cd15aea 100644
--- a/mk/PX4/config_px4fmu-v2_APM.mk
+++ b/mk/PX4/config_px4fmu-v2_APM.mk
@@ -61,7 +61,7 @@ MODULES		+= modules/uORB
 MODULES		+= lib/mathlib/math/filter
 MODULES	        += modules/libtomfastmath
 MODULES         += modules/libtomcrypt
-
+MODULES		+= lib/conversion
 
 #
 # Transitional support - add commands from the NuttX export archive.