diff --git a/include/common/assert_macros.S b/include/common/assert_macros.S
index 807972f..cb6c78b 100644
--- a/include/common/assert_macros.S
+++ b/include/common/assert_macros.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2015, 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:
@@ -27,6 +27,8 @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
+#ifndef __ASSERT_MACROS_S__
+#define __ASSERT_MACROS_S__
 
 	/*
 	 * Assembler macro to enable asm_assert. Use this macro wherever
@@ -47,3 +49,5 @@
 	mov	x1, __LINE__ ;\
 	b	asm_assert ;\
 300:
+
+#endif /* __ASSERT_MACROS_S__ */