diff --git a/src/sio/sio_w83877.c b/src/sio/sio_w83877.c
index 32e7a4bc8..a7a2b4ea2 100644
--- a/src/sio/sio_w83877.c
+++ b/src/sio/sio_w83877.c
@@ -202,7 +202,7 @@ w83877_lpt_handler(w83877_t *dev)
     lpt_port_irq(dev->lpt, lpt_irq);
     lpt_port_dma(dev->lpt, dev->dma_map[dev->regs[0x26] & 0x03]);
 
-    lpt_set_cnfgb_readout(dev->lpt, ((dev->regs[0x26] & 0xe0) >> 2) | 0x07);
+    lpt_set_cnfgb_readout(dev->lpt, ((dev->regs[0x27] & 0xe0) >> 2) | 0x07);
 }
 
 static void