diff --git a/src/sdk_config.h b/src/sdk_config.h
index 51d9e92f..1d22b54f 100644
--- a/src/sdk_config.h
+++ b/src/sdk_config.h
@@ -66,7 +66,7 @@
 #define HCI_MEM_POOL_ENABLED               1
 #define HCI_TX_BUF_SIZE                    600 // not used
 #define HCI_RX_BUF_SIZE                    600
-#define HCI_RX_BUF_QUEUE_SIZE              8   // must be power of 2
+#define HCI_RX_BUF_QUEUE_SIZE              16   // must be power of 2 (must be 16 for Nordic DFU to prevent overflow)
 
 //==========================================================
 // <e> UART_ENABLED - nrf_drv_uart - UART/UARTE peripheral driver