diff --git a/cpu.h b/cpu.h
index 7660464..2c6e8d1 100644
--- a/cpu.h
+++ b/cpu.h
@@ -6,10 +6,18 @@
 
   #include <avr/interrupt.h>
 
-#elif defined __ARMEL__
+#elif defined __ARM_LPC1114__
 
   #include "cmsis-lpc11xx.h"  // For __ASM().
 
+#elif defined __ARM_STM32F411__
+
+  #include "cmsis-stm32f4xx.h"  // For __ASM().
+
+#endif
+
+#if defined __ARMEL__
+
   /** Enable interrupts.
 
     This enables interrupts by clearing the I-bit in the CPSR.