diff --git a/components/esp_phy/src/phy_common.c b/components/esp_phy/src/phy_common.c
index 48607d49e2..0b30d9564d 100644
--- a/components/esp_phy/src/phy_common.c
+++ b/components/esp_phy/src/phy_common.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2023-2025 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2023-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -22,9 +22,13 @@
 #include "hal/temperature_sensor_ll.h"
 #endif
 
-#ifndef ANT_SEL0_IDX
-#define ANT_SEL0_IDX PAD_MODEM_ANT_SEL0_IDX
-#endif
+/* Per-target ANT_SELn_IDX indices are not always consecutive; do not use ANT_SEL0_IDX + n. */
+static const uint32_t s_phy_ant_sel_sig_idx[4] = {
+    ANT_SEL0_IDX,
+    ANT_SEL1_IDX,
+    ANT_SEL2_IDX,
+    ANT_SEL3_IDX,
+};
 
 static const char* TAG = "phy_comm";
 
@@ -200,7 +204,7 @@ esp_err_t esp_phy_set_ant_gpio(esp_phy_ant_gpio_config_t *config)
     for (int i = 0; i < 4; i++) {
         if (config->gpio_cfg[i].gpio_select == 1) {
             phy_ant_set_gpio_output(config->gpio_cfg[i].gpio_num);
-            esp_rom_gpio_connect_out_signal(config->gpio_cfg[i].gpio_num, ANT_SEL0_IDX + i, 0, 0);
+            esp_rom_gpio_connect_out_signal(config->gpio_cfg[i].gpio_num, s_phy_ant_sel_sig_idx[i], 0, 0);
         }
     }
 
diff --git a/components/soc/esp32s31/include/soc/gpio_sig_map.h b/components/soc/esp32s31/include/soc/gpio_sig_map.h
index d24ea6caa6..e0b5c32519 100644
--- a/components/soc/esp32s31/include/soc/gpio_sig_map.h
+++ b/components/soc/esp32s31/include/soc/gpio_sig_map.h
@@ -24,6 +24,8 @@
 #define SD_CARD_CDATA7_2_PAD_OUT_IDX            7
 #define PAD_MODEM_ANT_SEL0_IDX                  8
 #define PAD_MODEM_ANT_SEL1_IDX                  9
+#define ANT_SEL0_IDX                            PAD_MODEM_ANT_SEL0_IDX
+#define ANT_SEL1_IDX                            PAD_MODEM_ANT_SEL1_IDX
 #define UART0_RXD_PAD_IN_IDX                    10
 #define UART0_TXD_PAD_OUT_IDX                   10
 #define UART0_CTS_PAD_IN_IDX                    11
@@ -80,8 +82,10 @@
 #define I2S1_I_WS_PAD_OUT_IDX                   36
 #define PCNT1_RST_IN0_IDX                       37
 #define PAD_MODEM_ANT_SEL2_IDX                  37
+#define ANT_SEL2_IDX                            PAD_MODEM_ANT_SEL2_IDX
 #define PCNT1_RST_IN1_IDX                       38
 #define PAD_MODEM_ANT_SEL3_IDX                  38
+#define ANT_SEL3_IDX                            PAD_MODEM_ANT_SEL3_IDX
 #define PCNT1_RST_IN2_IDX                       39
 #define PAD_MODEM_ANT_SEL4_IDX                  39
 #define PCNT1_RST_IN3_IDX                       40