diff --git a/src/modules/position_estimator_inav/CMakeLists.txt b/src/modules/position_estimator_inav/CMakeLists.txt
index 518acd712a..10fcf57043 100644
--- a/src/modules/position_estimator_inav/CMakeLists.txt
+++ b/src/modules/position_estimator_inav/CMakeLists.txt
@@ -36,7 +36,7 @@ px4_add_module(
 	MAIN position_estimator_inav
 	STACK_MAIN 1200
 	STACK_MAX 4000
-	COMPILE_FLAGS
+	COMPILE_FLAGS -Os
 	SRCS
 		position_estimator_inav_main.cpp
 		position_estimator_inav_params.cpp