diff --git a/src/include/86box/serial.h b/src/include/86box/serial.h
index 63164bd57..8ed3606a7 100644
--- a/src/include/86box/serial.h
+++ b/src/include/86box/serial.h
@@ -53,9 +53,10 @@ typedef struct serial_s {
         dat, int_status, scratch, fcr,
         irq, type, inst, transmit_enabled,
         fifo_enabled, rcvr_fifo_len, bits, data_bits,
-        baud_cycles, rcvr_fifo_full, txsr, out, msr_set, pad, pad0, pad1;
+        baud_cycles, rcvr_fifo_full, txsr, out,
+        msr_set, pad, pad0, pad1;
 
-    uint16_t dlab, base_address, out_new;
+    uint16_t dlab, base_address, out_new, pad2;
 
     uint8_t rcvr_fifo_pos, xmit_fifo_pos,
         rcvr_fifo_end, xmit_fifo_end,