diff --git a/include/lib/spinlock.h b/include/lib/spinlock.h
index cb0bc3e..8273c78 100644
--- a/include/lib/spinlock.h
+++ b/include/lib/spinlock.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -31,11 +31,23 @@
 #ifndef __SPINLOCK_H__
 #define __SPINLOCK_H__
 
+#ifndef __ASSEMBLY__
+
+#include <types.h>
+
 typedef struct spinlock {
-	volatile unsigned int lock;
+	volatile uint32_t lock;
 } spinlock_t;
 
 void spin_lock(spinlock_t *lock);
 void spin_unlock(spinlock_t *lock);
 
+#else
+
+/* Spin lock definitions for use in assembly */
+#define SPINLOCK_ASM_ALIGN	2
+#define SPINLOCK_ASM_SIZE	4
+
+#endif
+
 #endif /* __SPINLOCK_H__ */