diff --git a/cores/esp32/Esp.h b/cores/esp32/Esp.h
index e23e607650e73da7db9f6684f4e639c3ac704bb7..334a489901a20dcf848c7e192bee12eeb376bfb4 100644
--- a/cores/esp32/Esp.h
+++ b/cores/esp32/Esp.h
@@ -55,7 +55,7 @@ public:
     ~EspClass() {}
     void restart();
     uint32_t getFreeHeap();
-    uint8_t getCpuFreqMHz(){ return F_CPU; }
+    uint8_t getCpuFreqMHz(){ return CONFIG_ESP32_DEFAULT_CPU_FREQ_MHZ; }
     uint32_t getCycleCount();
     const char * getSdkVersion();