+++ src/VBox/Devices/Bus/DevPCI.cpp
@@ -2279,7 +2280,7 @@
     /*
      * Register I/O ports and save state.
      */
-    rc = PDMDevHlpIOPortRegister(pDevIns, 0x0cf8, 1, NULL, pciIOPortAddressWrite, pciIOPortAddressRead, NULL, NULL, "i440FX (PCI)");
+    rc = PDMDevHlpIOPortRegister(pDevIns, 0x0cf8, 4, NULL, pciIOPortAddressWrite, pciIOPortAddressRead, NULL, NULL, "i440FX (PCI)");
     if (RT_FAILURE(rc))
         return rc;
     rc = PDMDevHlpIOPortRegister(pDevIns, 0x0cfc, 4, NULL, pciIOPortDataWrite, pciIOPortDataRead, NULL, NULL, "i440FX (PCI)");