diff --git a/components/esp8266/lib/VERSION b/components/esp8266/lib/VERSION
index f97de66c..87e5b6db 100644
--- a/components/esp8266/lib/VERSION
+++ b/components/esp8266/lib/VERSION
@@ -1,5 +1,5 @@
 gwen:
-    core:       e1fe83a
+    core:       71005fb
     net80211:   e1fe83a
     pp:         e1fe83a
     wpa:        e1fe83a
diff --git a/components/esp8266/lib/libcore.a b/components/esp8266/lib/libcore.a
index d8eda7af..597190a9 100755
Binary files a/components/esp8266/lib/libcore.a and b/components/esp8266/lib/libcore.a differ
diff --git a/components/esp8266/lib/libcore_dbg.a b/components/esp8266/lib/libcore_dbg.a
index 2a3fbce3..c3a01aa9 100755
Binary files a/components/esp8266/lib/libcore_dbg.a and b/components/esp8266/lib/libcore_dbg.a differ
diff --git a/components/esp8266/source/system_api.c b/components/esp8266/source/system_api.c
index c3c0402c..f464446a 100644
--- a/components/esp8266/source/system_api.c
+++ b/components/esp8266/source/system_api.c
@@ -32,6 +32,7 @@
 static const char* TAG = "system_api";
 
 static uint8_t base_mac_addr[6] = { 0 };
+uint32_t g_esp_ticks_per_us = 80;
 
 // Bootloader can get this information
 const __attribute__((section(".SystemInfoVector.text"))) esp_sys_info_t g_esp_sys_info = {
@@ -366,3 +367,18 @@ uint32_t esp_get_old_sysconf_addr(void)
 {
     return rtc_sys_info.old_sysconf_addr;
 }
+
+void os_update_cpu_frequency(uint32_t ticks_per_us)
+{
+    extern uint32_t _xt_tick_divisor;
+
+    if (REG_READ(DPORT_CTL_REG) & DPORT_CTL_DOUBLE_CLK) {
+        g_esp_ticks_per_us = CPU_CLK_FREQ * 2 / 1000000;
+        _xt_tick_divisor = (CPU_CLK_FREQ * 2 / CONFIG_FREERTOS_HZ);
+    } else {
+        g_esp_ticks_per_us = CPU_CLK_FREQ / 1000000;;
+        _xt_tick_divisor = (CPU_CLK_FREQ / CONFIG_FREERTOS_HZ);
+    }
+}
+
+void ets_update_cpu_frequency(uint32_t ticks_per_us) __attribute__((alias("os_update_cpu_frequency")));
diff --git a/components/freertos/port/esp8266/include/freertos/portmacro.h b/components/freertos/port/esp8266/include/freertos/portmacro.h
index 5d24707d..2955f9d2 100644
--- a/components/freertos/port/esp8266/include/freertos/portmacro.h
+++ b/components/freertos/port/esp8266/include/freertos/portmacro.h
@@ -213,7 +213,7 @@ void esp_increase_tick_cnt(const TickType_t ticks);
 extern void esp_vApplicationIdleHook( void );
 extern void esp_vApplicationTickHook( void );
 
-extern const uint32_t g_esp_ticks_per_us;
+extern uint32_t g_esp_ticks_per_us;
 
 /*
  * @brief Get FreeRTOS system idle ticks