diff --git a/boards/esp32_16M.json b/boards/esp32_16M.json
index 7d24cdac0..24eb490a7 100644
--- a/boards/esp32_16M.json
+++ b/boards/esp32_16M.json
@@ -5,7 +5,7 @@
     },
     "core": "esp32",
     "extra_flags": "-DARDUINO_ESP32_DEV",
-    "f_cpu": "800000000L",
+    "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dio",
     "mcu": "esp32",
diff --git a/boards/esp32_4M.json b/boards/esp32_4M.json
index ecb2d4027..53afbd219 100644
--- a/boards/esp32_4M.json
+++ b/boards/esp32_4M.json
@@ -5,7 +5,7 @@
     },
     "core": "esp32",
     "extra_flags": "-DARDUINO_ESP32_DEV",
-    "f_cpu": "800000000L",
+    "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dio",
     "mcu": "esp32",
diff --git a/boards/esp32_8M.json b/boards/esp32_8M.json
index 15c24ddcf..b390ebdf5 100644
--- a/boards/esp32_8M.json
+++ b/boards/esp32_8M.json
@@ -5,7 +5,7 @@
     },
     "core": "esp32",
     "extra_flags": "-DARDUINO_ESP32_DEV",
-    "f_cpu": "800000000L",
+    "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dio",
     "mcu": "esp32",