diff --git a/arch/cpu/arm/Makefile.arm b/arch/cpu/arm/Makefile.arm
index 9918fa053..ab3c5116f 100644
--- a/arch/cpu/arm/Makefile.arm
+++ b/arch/cpu/arm/Makefile.arm
@@ -29,7 +29,7 @@ SMALL ?= 1
 ifeq ($(SMALL),1)
   CFLAGS += -Os
 else
-  CFLAGS += -O0
+  CFLAGS += -O2
 endif
 
 ### Use CMSIS and the existing dbg-io from arch/cpu/arm/common