diff --git a/boot/zephyr/main.c b/boot/zephyr/main.c
index 3664a8b..837228b 100644
--- a/boot/zephyr/main.c
+++ b/boot/zephyr/main.c
@@ -183,7 +183,6 @@
                                      rsp->br_image_off +
                                      rsp->br_hdr->ih_hdr_size);
 
-    irq_lock();
 #ifdef CONFIG_SYS_CLOCK_EXISTS
     sys_clock_disable();
 #endif
@@ -202,6 +201,8 @@
 
 #if CONFIG_CPU_HAS_ARM_MPU || CONFIG_CPU_HAS_NXP_MPU
     z_arm_clear_arm_mpu_config();
+#else
+    irq_lock();
 #endif
 
 #if defined(CONFIG_BUILTIN_STACK_GUARD) && \