diff --git a/components/esp_hw_support/port/esp32c6/rtc_clk.c b/components/esp_hw_support/port/esp32c6/rtc_clk.c
index 3beac67c3c..015a002562 100644
--- a/components/esp_hw_support/port/esp32c6/rtc_clk.c
+++ b/components/esp_hw_support/port/esp32c6/rtc_clk.c
@@ -362,6 +362,7 @@ soc_xtal_freq_t rtc_clk_xtal_freq_get(void)
     uint32_t xtal_freq_mhz = clk_ll_xtal_load_freq_mhz();
     if (xtal_freq_mhz == 0) {
         ESP_HW_LOGW(TAG, "invalid RTC_XTAL_FREQ_REG value, assume 40MHz");
+        clk_ll_xtal_store_freq_mhz(SOC_XTAL_FREQ_40M);
         return SOC_XTAL_FREQ_40M;
     }
     return (soc_xtal_freq_t)xtal_freq_mhz;