diff --git a/src/drivers/airspeed/module.mk b/src/drivers/airspeed/module.mk
index 4eef061610..5fbc75309c 100644
--- a/src/drivers/airspeed/module.mk
+++ b/src/drivers/airspeed/module.mk
@@ -36,3 +36,5 @@
 #
 
 SRCS			= airspeed.cpp
+
+MAXOPTIMIZATION	 = -Os
diff --git a/src/drivers/bma180/module.mk b/src/drivers/bma180/module.mk
index 4c60ee082c..33433307a6 100644
--- a/src/drivers/bma180/module.mk
+++ b/src/drivers/bma180/module.mk
@@ -38,3 +38,5 @@
 MODULE_COMMAND	= bma180
 
 SRCS		= bma180.cpp
+
+MAXOPTIMIZATION	 = -Os
diff --git a/src/drivers/ets_airspeed/module.mk b/src/drivers/ets_airspeed/module.mk
index 966a5b8190..8aaaf0ebb0 100644
--- a/src/drivers/ets_airspeed/module.mk
+++ b/src/drivers/ets_airspeed/module.mk
@@ -40,3 +40,5 @@ MODULE_COMMAND		= ets_airspeed
 SRCS			= ets_airspeed.cpp
 
 MODULE_STACKSIZE	= 1200
+
+MAXOPTIMIZATION	 = -Os
diff --git a/src/drivers/hil/module.mk b/src/drivers/hil/module.mk
index f8895f5d5a..f1fc49fb3d 100644
--- a/src/drivers/hil/module.mk
+++ b/src/drivers/hil/module.mk
@@ -38,3 +38,5 @@
 MODULE_COMMAND	= hil
 
 SRCS		= hil.cpp
+
+MAXOPTIMIZATION	 = -Os
diff --git a/src/drivers/led/module.mk b/src/drivers/led/module.mk
index 777f3e4425..5b7b4491b7 100644
--- a/src/drivers/led/module.mk
+++ b/src/drivers/led/module.mk
@@ -36,3 +36,5 @@
 #
 
 SRCS		= led.cpp
+
+MAXOPTIMIZATION	 = -Os
diff --git a/src/drivers/md25/module.mk b/src/drivers/md25/module.mk
index 13821a6b58..3f9cf2d891 100644
--- a/src/drivers/md25/module.mk
+++ b/src/drivers/md25/module.mk
@@ -40,3 +40,5 @@ MODULE_COMMAND		= md25
 
 SRCS			= md25.cpp \
 			  md25_main.cpp
+
+MAXOPTIMIZATION	 = -Os
diff --git a/src/drivers/meas_airspeed/module.mk b/src/drivers/meas_airspeed/module.mk
index 2a15b669f4..6f5909978b 100644
--- a/src/drivers/meas_airspeed/module.mk
+++ b/src/drivers/meas_airspeed/module.mk
@@ -42,3 +42,5 @@ SRCS			= meas_airspeed.cpp
 MODULE_STACKSIZE	= 1200
 
 EXTRACXXFLAGS	= -Weffc++
+
+MAXOPTIMIZATION	 = -Os
diff --git a/src/drivers/ms5611/module.mk b/src/drivers/ms5611/module.mk
index 20f8aa1737..ee74058fc1 100644
--- a/src/drivers/ms5611/module.mk
+++ b/src/drivers/ms5611/module.mk
@@ -38,3 +38,5 @@
 MODULE_COMMAND	= ms5611
 
 SRCS		= ms5611.cpp ms5611_spi.cpp ms5611_i2c.cpp
+
+MAXOPTIMIZATION	 = -Os
diff --git a/src/drivers/px4flow/module.mk b/src/drivers/px4flow/module.mk
index d3062e4579..460bec7b96 100644
--- a/src/drivers/px4flow/module.mk
+++ b/src/drivers/px4flow/module.mk
@@ -38,3 +38,5 @@
 MODULE_COMMAND	= px4flow
 
 SRCS		= px4flow.cpp
+
+MAXOPTIMIZATION	 = -Os
diff --git a/src/drivers/roboclaw/module.mk b/src/drivers/roboclaw/module.mk
index 1abecf198b..c5e55bdc30 100644
--- a/src/drivers/roboclaw/module.mk
+++ b/src/drivers/roboclaw/module.mk
@@ -39,3 +39,5 @@ MODULE_COMMAND		= roboclaw
 
 SRCS			= roboclaw_main.cpp \
 			  RoboClaw.cpp
+
+MAXOPTIMIZATION	 = -Os