diff --git a/esp32/uwb_anchor/src/main.cpp b/esp32/uwb_anchor/src/main.cpp
index c208949..f9aa5f2 100644
--- a/esp32/uwb_anchor/src/main.cpp
+++ b/esp32/uwb_anchor/src/main.cpp
@@ -77,16 +77,16 @@ struct EspNowPacket {
 
 /* ISR ring buffer for ESP-NOW */
 #define ESPNOW_Q_SIZE  8
-static volatile EspNowPacket g_enq[ESPNOW_Q_SIZE];
+static EspNowPacket g_enq[ESPNOW_Q_SIZE];
 static volatile int g_en_head = 0, g_en_tail = 0;
 
-static void IRAM_ATTR espnow_rx_cb(const uint8_t *mac, const uint8_t *data, int len) {
+static void IRAM_ATTR espnow_rx_cb(const esp_now_recv_info_t *info, const uint8_t *data, int len) {
     if (len < (int)sizeof(EspNowPacket)) return;
     const EspNowPacket *p = (const EspNowPacket *)data;
     if (p->magic[0] != ESPNOW_MAGIC_0 || p->magic[1] != ESPNOW_MAGIC_1) return;
     int next = (g_en_head + 1) % ESPNOW_Q_SIZE;
     if (next == g_en_tail) return;
-    g_enq[g_en_head] = *p;
+    memcpy(&g_enq[g_en_head], p, sizeof(EspNowPacket));
     g_en_head = next;
 }