diff --git a/components/esp_phy/esp32c61/include/phy_init_data.h b/components/esp_phy/esp32c61/include/phy_init_data.h
index 5eba2765042..ef8c700d28f 100644
--- a/components/esp_phy/esp32c61/include/phy_init_data.h
+++ b/components/esp_phy/esp32c61/include/phy_init_data.h
@@ -27,8 +27,8 @@ extern "C" {
 #if CONFIG_ESP_PHY_MULTIPLE_INIT_DATA_BIN
 #define PHY_CRC_ALGORITHM 1
 #define PHY_COUNTRY_CODE_LEN 2
-#define PHY_INIT_DATA_TYPE_OFFSET 254
-#define PHY_SUPPORT_MULTIPLE_BIN_OFFSET 253
+#define PHY_INIT_DATA_TYPE_OFFSET 126
+#define PHY_SUPPORT_MULTIPLE_BIN_OFFSET 125
 #endif
 
 extern const char phy_init_magic_pre[];
diff --git a/components/esp_phy/esp32s31/include/phy_init_data.h b/components/esp_phy/esp32s31/include/phy_init_data.h
index e2eeb7078d4..b98f9d06a73 100644
--- a/components/esp_phy/esp32s31/include/phy_init_data.h
+++ b/components/esp_phy/esp32s31/include/phy_init_data.h
@@ -27,8 +27,8 @@ extern "C" {
 #if CONFIG_ESP_PHY_MULTIPLE_INIT_DATA_BIN
 #define PHY_CRC_ALGORITHM 1
 #define PHY_COUNTRY_CODE_LEN 2
-#define PHY_INIT_DATA_TYPE_OFFSET 254
-#define PHY_SUPPORT_MULTIPLE_BIN_OFFSET 253
+#define PHY_INIT_DATA_TYPE_OFFSET 126
+#define PHY_SUPPORT_MULTIPLE_BIN_OFFSET 125
 #endif
 
 extern const char phy_init_magic_pre[];
diff --git a/components/esp_phy/src/phy_init.c b/components/esp_phy/src/phy_init.c
index 08284f04bf5..9b3043ef21a 100644
--- a/components/esp_phy/src/phy_init.c
+++ b/components/esp_phy/src/phy_init.c
@@ -126,6 +126,13 @@ static uint8_t s_phy_modem_init_ref = 0;
 extern uint8_t multi_phy_init_data_bin_start[] asm("_binary_phy_multiple_init_data_bin_start");
 extern uint8_t multi_phy_init_data_bin_end[]   asm("_binary_phy_multiple_init_data_bin_end");
 #endif
+
+/* Both flags live in the last bytes of an init data entry */
+_Static_assert(PHY_INIT_DATA_TYPE_OFFSET == sizeof(esp_phy_init_data_t) - 2,
+               "PHY_INIT_DATA_TYPE_OFFSET does not match the PHY init data of this target");
+_Static_assert(PHY_SUPPORT_MULTIPLE_BIN_OFFSET == sizeof(esp_phy_init_data_t) - 3,
+               "PHY_SUPPORT_MULTIPLE_BIN_OFFSET does not match the PHY init data of this target");
+
 /* The following static variables are only used by Wi-Fi tasks, so they can be handled without lock */
 static phy_init_data_type_t s_phy_init_data_type = 0;