diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 3f0a647218e4..c0a6992933e4 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -454,7 +454,8 @@ config NR_CPUS
 	range 2 32 if RISCV_SBI_V01 && 32BIT
 	range 2 64 if RISCV_SBI_V01 && 64BIT
 	default "32" if 32BIT
-	default "64" if 64BIT
+	default "64" if RISCV_SBI_V01 && 64BIT
+	default "256" if !RISCV_SBI_V01 && 64BIT
 
 config HOTPLUG_CPU
 	bool "Support for hot-pluggable CPUs"