diff --git a/arch/xtensa/src/esp32/esp32_rt_timer.h b/arch/xtensa/src/esp32/esp32_rt_timer.h
index 68ee2922af4..afbeaee8808 100644
--- a/arch/xtensa/src/esp32/esp32_rt_timer.h
+++ b/arch/xtensa/src/esp32/esp32_rt_timer.h
@@ -31,9 +31,17 @@
 #include <sys/types.h>
 #include <nuttx/list.h>
 
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
 #define RT_TIMER_NOFLAGS    (0)         /* Timer support no feature */
 #define RT_TIMER_REPEAT     (1 << 0)    /* Timer is repeat */
 
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
 /**
  * RT timer state
  */
@@ -80,6 +88,10 @@ extern "C"
 #define EXTERN extern
 #endif
 
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
 /****************************************************************************
  * Name: rt_timer_create
  *