diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index 61a772d..fec63ca 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -278,7 +278,7 @@
     default_firmware = x86_machine_is_acpi_enabled(x86ms)
             ? MICROVM_BIOS_FILENAME
             : MICROVM_QBOOT_FILENAME;
-    x86_bios_rom_init(MACHINE(mms), default_firmware, get_system_memory(), true);
+    x86_bios_rom_init(x86ms, default_firmware, get_system_memory(), true);
 }
 
 static void microvm_memory_init(MicrovmMachineState *mms)
diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index 87b5bf5..59c7a81 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -205,7 +205,7 @@
     BlockBackend *pflash_blk[ARRAY_SIZE(pcms->flash)];
 
     if (!pcmc->pci_enabled) {
-        x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, true);
+        x86_bios_rom_init(X86_MACHINE(pcms), "bios.bin", rom_memory, true);
         return;
     }
 
@@ -226,7 +226,7 @@
 
     if (!pflash_blk[0]) {
         /* Machine property pflash0 not set, use ROM mode */
-        x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, false);
+        x86_bios_rom_init(X86_MACHINE(pcms), "bios.bin", rom_memory, false);
     } else {
         if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
             /*
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 2a4f3ee..6d3c72f 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -1128,7 +1128,7 @@
     nb_option_roms++;
 }
 
-void x86_bios_rom_init(MachineState *ms, const char *default_firmware,
+void x86_bios_rom_init(X86MachineState *x86ms, const char *default_firmware,
                        MemoryRegion *rom_memory, bool isapc_ram_fw)
 {
     const char *bios_name;
@@ -1138,7 +1138,7 @@
     ssize_t ret;
 
     /* BIOS load */
-    bios_name = ms->firmware ?: default_firmware;
+    bios_name = MACHINE(x86ms)->firmware ?: default_firmware;
     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
     if (filename) {
         bios_size = get_image_size(filename);
diff --git a/include/hw/i386/x86.h b/include/hw/i386/x86.h
index 4dc30dc..cb07618 100644
--- a/include/hw/i386/x86.h
+++ b/include/hw/i386/x86.h
@@ -116,7 +116,7 @@
 void x86_cpu_unplug_cb(HotplugHandler *hotplug_dev,
                        DeviceState *dev, Error **errp);
 
-void x86_bios_rom_init(MachineState *ms, const char *default_firmware,
+void x86_bios_rom_init(X86MachineState *x86ms, const char *default_firmware,
                        MemoryRegion *rom_memory, bool isapc_ram_fw);
 
 void x86_load_linux(X86MachineState *x86ms,