diff --git a/west.yml b/west.yml
index cc4c437..f76966f 100644
--- a/west.yml
+++ b/west.yml
@@ -5,5 +5,5 @@ manifest:
   projects:
     - name: zephyr
       remote: zephyrproject-rtos
-      revision: v3.7.0
+      revision: v4.0.0
       import: true
diff --git a/zephyr/drivers/serial/uart_bitbang.c b/zephyr/drivers/serial/uart_bitbang.c
index 1d606cb..927b3a0 100644
--- a/zephyr/drivers/serial/uart_bitbang.c
+++ b/zephyr/drivers/serial/uart_bitbang.c
@@ -8,6 +8,7 @@
 #include <zephyr/arch/cpu.h>
 #include <zephyr/device.h>
 #include <zephyr/drivers/uart.h>
+#include <soc.h>
 
 #define DT_DRV_COMPAT olofk_serial
 
diff --git a/zephyr/soc/riscv/servant/Kconfig.defconfig b/zephyr/soc/riscv/servant/Kconfig.defconfig
index 8479a98..607f6ff 100644
--- a/zephyr/soc/riscv/servant/Kconfig.defconfig
+++ b/zephyr/soc/riscv/servant/Kconfig.defconfig
@@ -23,4 +23,16 @@ config SERV_TIMER
 	bool
 	default y
 
+config ARCH_HAS_CUSTOM_CPU_IDLE
+        bool
+        default y
+
+config ARCH_HAS_CUSTOM_CPU_ATOMIC_IDLE
+        bool
+        default y
+
+config RISCV_SOC_EXCEPTION_FROM_IRQ
+	bool
+	default y
+
 endif # SOC_RISCV32_SERVANT