diff --git a/boards/esp32_16M.json b/boards/esp32_16M.json
index 24eb490a7..f94e36493 100644
--- a/boards/esp32_16M.json
+++ b/boards/esp32_16M.json
@@ -4,7 +4,7 @@
       "ldscript": "esp32_out.ld"
     },
     "core": "esp32",
-    "extra_flags": "-DARDUINO_ESP32_DEV",
+    "extra_flags": "-DARDUINO_ESP32_DEV -DESP32_16M",
     "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dio",
diff --git a/boards/esp32_4M.json b/boards/esp32_4M.json
index 53afbd219..c55367e2e 100644
--- a/boards/esp32_4M.json
+++ b/boards/esp32_4M.json
@@ -4,7 +4,7 @@
       "ldscript": "esp32_out.ld"
     },
     "core": "esp32",
-    "extra_flags": "-DARDUINO_ESP32_DEV",
+    "extra_flags": "-DARDUINO_ESP32_DEV -DESP32_4M",
     "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dio",
diff --git a/boards/esp32_8M.json b/boards/esp32_8M.json
index b390ebdf5..d52b2c48f 100644
--- a/boards/esp32_8M.json
+++ b/boards/esp32_8M.json
@@ -4,7 +4,7 @@
       "ldscript": "esp32_out.ld"
     },
     "core": "esp32",
-    "extra_flags": "-DARDUINO_ESP32_DEV",
+    "extra_flags": "-DARDUINO_ESP32_DEV -DESP32_8M",
     "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dio",
diff --git a/boards/esp8266_1M.json b/boards/esp8266_1M.json
index 6c2287c6a..bc5b1f49b 100644
--- a/boards/esp8266_1M.json
+++ b/boards/esp8266_1M.json
@@ -4,7 +4,7 @@
       "ldscript": "eagle.flash.1m.ld"
     },
     "core": "esp8266",
-    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01",
+    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01 -DESP8266_1M",
     "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dout",
diff --git a/boards/esp8266_2M1M.json b/boards/esp8266_2M1M.json
index e659a3f90..e3a675373 100644
--- a/boards/esp8266_2M1M.json
+++ b/boards/esp8266_2M1M.json
@@ -4,7 +4,7 @@
       "ldscript": "eagle.flash.2m1m.ld"
     },
     "core": "esp8266",
-    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01",
+    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01 -DESP8266_2M -DESP8266_2M1M",
     "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dout",
diff --git a/boards/esp8266_2M256.json b/boards/esp8266_2M256.json
index 24a3ced47..734f62537 100644
--- a/boards/esp8266_2M256.json
+++ b/boards/esp8266_2M256.json
@@ -4,7 +4,7 @@
       "ldscript": "eagle.flash.2m256.ld"
     },
     "core": "esp8266",
-    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01",
+    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01 -DESP8266_2M -DESP8266_2M256",
     "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dout",
diff --git a/boards/esp8266_4M2M.json b/boards/esp8266_4M2M.json
index 616384b40..873c84f24 100644
--- a/boards/esp8266_4M2M.json
+++ b/boards/esp8266_4M2M.json
@@ -4,7 +4,7 @@
       "ldscript": "eagle.flash.4m2m.ld"
     },
     "core": "esp8266",
-    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01",
+    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01 -DESP8266_4M -DESP8266_4M2M",
     "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dout",
diff --git a/boards/esp8266_4M3M.json b/boards/esp8266_4M3M.json
index efca2d7e2..c845d6e96 100644
--- a/boards/esp8266_4M3M.json
+++ b/boards/esp8266_4M3M.json
@@ -4,7 +4,7 @@
       "ldscript": "eagle.flash.4m3m.ld"
     },
     "core": "esp8266",
-    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01",
+    "extra_flags": "-DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01 -DESP8266_4M -DESP8266_4M3M",
     "f_cpu": "80000000L",
     "f_flash": "40000000L",
     "flash_mode": "dout",