diff --git a/arch/xtensa/src/esp32s3/esp32s3_spiflash.c b/arch/xtensa/src/esp32s3/esp32s3_spiflash.c
index f17408631f..fc943f265a 100644
--- a/arch/xtensa/src/esp32s3/esp32s3_spiflash.c
+++ b/arch/xtensa/src/esp32s3/esp32s3_spiflash.c
@@ -285,22 +285,26 @@ static void spiflash_resume_cache(void)
 static void spiflash_start(void)
 {
   struct tcb_s *tcb = this_task();
-  int cpu = up_cpu_index();
   int saved_priority = tcb->sched_priority;
+  int cpu;
 #ifdef CONFIG_SMP
-  int other_cpu = cpu ? 0 : 1;
+  int other_cpu;
 #endif
 
   nxrmutex_lock(&g_flash_op_mutex);
 
-  DEBUGASSERT(cpu == 0 || cpu == 1);
-
   /* Temporary raise schedule priority */
 
   nxsched_set_priority(tcb, SCHED_PRIORITY_MAX);
 
+  cpu = up_cpu_index();
 #ifdef CONFIG_SMP
+  other_cpu = cpu == 1 ? 0 : 1;
+#endif
 
+  DEBUGASSERT(cpu == 0 || cpu == 1);
+
+#ifdef CONFIG_SMP
   DEBUGASSERT(other_cpu == 0 || other_cpu == 1);
   DEBUGASSERT(other_cpu != cpu);
   if (OSINIT_OS_READY())