diff --git a/src/rtos/zephyr.c b/src/rtos/zephyr.c
index e5d683507..3ef9bcd2c 100644
--- a/src/rtos/zephyr.c
+++ b/src/rtos/zephyr.c
@@ -189,9 +189,9 @@ enum zephyr_symbol_values {
 	ZEPHYR_VAL_COUNT
 };
 
-static int64_t zephyr_cortex_m_stack_align(struct target *target,
+static target_addr_t zephyr_cortex_m_stack_align(struct target *target,
 		const uint8_t *stack_data,
-		const struct rtos_register_stacking *stacking, int64_t stack_ptr)
+		const struct rtos_register_stacking *stacking, target_addr_t stack_ptr)
 {
 	return rtos_Cortex_M_stack_align(target, stack_data, stacking,
 			stack_ptr, ARM_XPSR_OFFSET);