diff --git a/src/network/net_rtl8139.c b/src/network/net_rtl8139.c
index 5138b5168..0d07a8f83 100644
--- a/src/network/net_rtl8139.c
+++ b/src/network/net_rtl8139.c
@@ -2549,6 +2549,12 @@ rtl8139_io_writeb(uint32_t addr, uint8_t val, void *priv)
 
             break;
 
+        case RxConfig:
+            rtl8139_log("RxConfig write(b) val=0x%02x\n", val);
+            rtl8139_RxConfig_write(s,
+                (rtl8139_RxConfig_read(s) & 0xFFFFFF00) | val);
+            break;
+
         default:
             rtl8139_log("not implemented write(b) addr=0x%x val=0x%02x\n", addr, val);
             break;