diff --git a/sys/arm/include/asm.h b/sys/arm/include/asm.h
--- a/sys/arm/include/asm.h
+++ b/sys/arm/include/asm.h
@@ -207,11 +207,6 @@
 #define DSB	mcr CP15_CP15DSB
 #define DMB	mcr CP15_CP15DMB
 #define WFI	mcr CP15_CP15WFI
-#else
-#define ISB	mcr CP15_CP15ISB
-#define DSB	mcr CP15_CP15DSB	/* DSB and DMB are the */
-#define DMB	mcr CP15_CP15DSB	/* same prior to v6.*/
-/* No form of WFI available on v4, define nothing to get an error on use. */
 #endif
 
 #endif /* !_MACHINE_ASM_H_ */