diff --git a/components/ulp/lp_core/lp_core/include/ulp_lp_core_utils.h b/components/ulp/lp_core/lp_core/include/ulp_lp_core_utils.h
index 4b6065c6b1..48ab1529ba 100644
--- a/components/ulp/lp_core/lp_core/include/ulp_lp_core_utils.h
+++ b/components/ulp/lp_core/lp_core/include/ulp_lp_core_utils.h
@@ -18,6 +18,8 @@ extern "C" {
 /**
  * @brief Traverse all possible wake-up sources and update the wake-up cause so that
  *        ulp_lp_core_get_wakeup_cause can obtain the bitmap of the wake-up reasons.
+ * @note Do not call it from user ULP programs because it will clear the wake-up cause bits
+ *       which were set at ULP startup in lp_core_startup().
  */
 void ulp_lp_core_update_wakeup_cause(void);
 
diff --git a/components/ulp/lp_core/lp_core/lp_core_utils.c b/components/ulp/lp_core/lp_core/lp_core_utils.c
index 4a9bdb8a54..7bada098ca 100644
--- a/components/ulp/lp_core/lp_core/lp_core_utils.c
+++ b/components/ulp/lp_core/lp_core/lp_core_utils.c
@@ -42,6 +42,7 @@ static uint32_t lp_wakeup_cause = 0;
 
 void ulp_lp_core_update_wakeup_cause(void)
 {
+    lp_wakeup_cause = 0;
     if ((lp_core_ll_get_wakeup_source() & LP_CORE_LL_WAKEUP_SOURCE_HP_CPU) \
             && (pmu_ll_lp_get_interrupt_raw(&PMU) & PMU_HP_SW_TRIGGER_INT_RAW)) {
         lp_wakeup_cause |= LP_CORE_LL_WAKEUP_SOURCE_HP_CPU;