diff --git a/board/build.mk b/board/build.mk
index 069a00e1a04058..d662f6b1419ad6 100644
--- a/board/build.mk
+++ b/board/build.mk
@@ -1,4 +1,4 @@
-CFLAGS += -I inc -I ../ -nostdlib -fno-builtin -std=gnu11 -O0
+CFLAGS += -I inc -I ../ -nostdlib -fno-builtin -std=gnu11 -O2
 CFLAGS += -Tstm32_flash.ld
 
 CC = arm-none-eabi-gcc