diff --git a/arch/renesas/src/rx65n/rx65n_cgc.c b/arch/renesas/src/rx65n/rx65n_cgc.c
index 08571823cf5..79f764c91ea 100644
--- a/arch/renesas/src/rx65n/rx65n_cgc.c
+++ b/arch/renesas/src/rx65n/rx65n_cgc.c
@@ -39,7 +39,9 @@
 
 void r_cgc_create(void)
 {
+#ifdef CONFIG_RX65N_RTC
   volatile uint8_t i;
+#endif
 #if ((24 * RX_CLK_1MHz) == RX_RESONATOR)
   /* Set main clock control registers */
 
diff --git a/boards/renesas/rx65n/rx65n-grrose/src/rx65n_bringup.c b/boards/renesas/rx65n/rx65n-grrose/src/rx65n_bringup.c
index c756b9d04f0..b366487ce4a 100644
--- a/boards/renesas/rx65n/rx65n-grrose/src/rx65n_bringup.c
+++ b/boards/renesas/rx65n/rx65n-grrose/src/rx65n_bringup.c
@@ -106,6 +106,7 @@ static int rtc_driver_initialize(void)
 
 int rx65n_bringup(void)
 {
+#if defined (HAVE_RTC_DRIVER) || defined (CONFIG_FS_PROCFS)
   int ret;
 #ifdef HAVE_RTC_DRIVER
   ret = rtc_driver_initialize();
@@ -128,6 +129,7 @@ int rx65n_bringup(void)
     }
 
 #endif
+#endif
 
 #ifdef CONFIG_RX65N_SBRAM
   /* Initialize battery-backed RAM */
diff --git a/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_appinit.c b/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_appinit.c
index 1de40128594..17e26a934b8 100644
--- a/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_appinit.c
+++ b/boards/renesas/rx65n/rx65n-rsk2mb/src/rx65n_appinit.c
@@ -28,6 +28,7 @@
 #include <stdint.h>
 
 #include <nuttx/board.h>
+#include "rx65n_rsk2mb.h"
 
 #ifdef CONFIG_LIB_BOARDCTL