diff --git a/src/Makefile b/src/Makefile
index e8e985c..06813c5 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -62,7 +62,7 @@ SRC =			\
 
 include $(PLATFORM_DIR)/Makefile.inc
 
-OPT_FLAGS ?= -Og
+OPT_FLAGS ?= -Os
 CFLAGS += $(OPT_FLAGS)
 LDFLAGS += $(OPT_FLAGS)
 
diff --git a/src/platforms/stlink/Makefile.inc b/src/platforms/stlink/Makefile.inc
index a1d74f5..7d79dd1 100644
--- a/src/platforms/stlink/Makefile.inc
+++ b/src/platforms/stlink/Makefile.inc
@@ -3,7 +3,6 @@ ST_BOOTLOADER ?=
 CC = $(CROSS_COMPILE)gcc
 OBJCOPY = $(CROSS_COMPILE)objcopy
 
-OPT_FLAGS = -Os
 CFLAGS += -mcpu=cortex-m3 -mthumb \
 	-DSTM32F1 -DDISCOVERY_STLINK -I../libopencm3/include \
 	-I platforms/stm32
diff --git a/src/platforms/swlink/Makefile.inc b/src/platforms/swlink/Makefile.inc
index 5cad72e..18841fb 100644
--- a/src/platforms/swlink/Makefile.inc
+++ b/src/platforms/swlink/Makefile.inc
@@ -2,7 +2,6 @@ CROSS_COMPILE ?= arm-none-eabi-
 CC = $(CROSS_COMPILE)gcc
 OBJCOPY = $(CROSS_COMPILE)objcopy
 
-OPT_FLAGS = -Os
 CFLAGS += -mcpu=cortex-m3 -mthumb \
 	-DSTM32F1 -DDISCOVERY_SWLINK -I../libopencm3/include \
 	-I platforms/stm32