diff --git a/arch/riscv/core/pmp.c b/arch/riscv/core/pmp.c
index 862e63619e594..0eac0219afa56 100644
--- a/arch/riscv/core/pmp.c
+++ b/arch/riscv/core/pmp.c
@@ -48,8 +48,6 @@ LOG_MODULE_REGISTER(mpu);
 #define PMP_NA4_SUPPORTED	!IS_ENABLED(CONFIG_PMP_NO_NA4)
 #define PMP_NAPOT_SUPPORTED	!IS_ENABLED(CONFIG_PMP_NO_NAPOT)
 
-#define PMPCFG_STRIDE sizeof(unsigned long)
-
 #define PMP_ADDR(addr)			((addr) >> 2)
 #define NAPOT_RANGE(size)		(((size) - 1) >> 1)
 #define PMP_ADDR_NAPOT(addr, size)	PMP_ADDR(addr | NAPOT_RANGE(size))
@@ -562,7 +560,7 @@ void z_riscv_pmp_stackguard_disable(void)
 {
 
 	unsigned long pmp_addr[CONFIG_PMP_SLOTS];
-	unsigned long pmp_cfg[CONFIG_PMP_SLOTS / sizeof(unsigned long)];
+	unsigned long pmp_cfg[CONFIG_PMP_SLOTS / PMPCFG_STRIDE];
 	unsigned int index = global_pmp_end_index;
 
 	/* Retrieve the pmpaddr value matching the last global PMP slot. */
diff --git a/arch/riscv/include/pmp.h b/arch/riscv/include/pmp.h
index ca4f37f3a2aba..25b3f1fa0df00 100644
--- a/arch/riscv/include/pmp.h
+++ b/arch/riscv/include/pmp.h
@@ -7,6 +7,8 @@
 #ifndef PMP_H_
 #define PMP_H_
 
+#define PMPCFG_STRIDE (__riscv_xlen / 8)
+
 void z_riscv_pmp_init(void);
 void z_riscv_pmp_stackguard_prepare(struct k_thread *thread);
 void z_riscv_pmp_stackguard_enable(struct k_thread *thread);
diff --git a/include/zephyr/arch/riscv/thread.h b/include/zephyr/arch/riscv/thread.h
index 81376681cdbe6..c1e6e8358cc23 100644
--- a/include/zephyr/arch/riscv/thread.h
+++ b/include/zephyr/arch/riscv/thread.h
@@ -72,7 +72,7 @@ struct _thread_arch {
 #ifdef CONFIG_USERSPACE
 	unsigned long priv_stack_start;
 	unsigned long u_mode_pmpaddr_regs[CONFIG_PMP_SLOTS];
-	unsigned long u_mode_pmpcfg_regs[CONFIG_PMP_SLOTS / sizeof(unsigned long)];
+	unsigned long u_mode_pmpcfg_regs[CONFIG_PMP_SLOTS / (__riscv_xlen / 8)];
 	unsigned int u_mode_pmp_domain_offset;
 	unsigned int u_mode_pmp_end_index;
 	unsigned int u_mode_pmp_update_nr;
@@ -80,7 +80,7 @@ struct _thread_arch {
 #ifdef CONFIG_PMP_STACK_GUARD
 	unsigned int m_mode_pmp_end_index;
 	unsigned long m_mode_pmpaddr_regs[CONFIG_PMP_SLOTS];
-	unsigned long m_mode_pmpcfg_regs[CONFIG_PMP_SLOTS / sizeof(unsigned long)];
+	unsigned long m_mode_pmpcfg_regs[CONFIG_PMP_SLOTS / (__riscv_xlen / 8)];
 #endif
 };