diff --git a/sdkconfig.defaults b/sdkconfig.defaults
index 5f6ba8e..76f5eac 100644
--- a/sdkconfig.defaults
+++ b/sdkconfig.defaults
@@ -67,3 +67,14 @@ CONFIG_MBEDTLS_DYNAMIC_BUFFER=y
 # The line below selects the dynamic choice; Kconfig will silently revert to
 # static when PSRAM+WiFi alloc is active — this is expected behaviour.
 CONFIG_ESP_WIFI_DYNAMIC_TX_BUFFER=y
+
+# --- Wi-Fi RAM tuning (BOX-3 internal RAM is tight; restore lost runtime tuning)
+# esp_wifi_init NO_MEM came from too many static RX buffers in internal DRAM.
+CONFIG_ESP_WIFI_STATIC_RX_BUFFER_NUM=6
+CONFIG_ESP_WIFI_DYNAMIC_RX_BUFFER_NUM=24
+CONFIG_ESP_WIFI_DYNAMIC_TX_BUFFER_NUM=24
+CONFIG_ESP_WIFI_AMPDU_TX_ENABLED=y
+CONFIG_ESP_WIFI_AMPDU_RX_ENABLED=y
+CONFIG_ESP_WIFI_RX_BA_WIN=6
+CONFIG_MBEDTLS_DYNAMIC_FREE_CA_CERT=y
+CONFIG_ESP_WIFI_STATIC_TX_BUFFER_NUM=4