diff --git a/arch/sim/include/spinlock.h b/arch/sim/include/spinlock.h
index 7be71df071..2e760f1533 100644
--- a/arch/sim/include/spinlock.h
+++ b/arch/sim/include/spinlock.h
@@ -39,12 +39,13 @@
 /****************************************************************************
  * Public Types
  ****************************************************************************/
+
 /* Must match definitions in up_testset.c */
 
 typedef uint8_t spinlock_t;
 
 /****************************************************************************
- * Public Functions
+ * Public Functions Prototypes
  ****************************************************************************/
 
 /****************************************************************************