diff --git a/src/video/vid_s3_virge.c b/src/video/vid_s3_virge.c
index 376abb68c..e2ecf8ae5 100644
--- a/src/video/vid_s3_virge.c
+++ b/src/video/vid_s3_virge.c
@@ -4181,10 +4181,13 @@ s3_virge_init(const device_t *info)
               s3_virge_overlay_draw);
     virge->svga.hwcursor.cur_ysize = 64;
 
-    if (info->local == S3_VIRGE_GX2)
-        rom_init(&virge->bios_rom, (char *) bios_fn, 0xc0000, 0x10000, 0xffff, 0, MEM_MAPPING_EXTERNAL);
-    else
-        rom_init(&virge->bios_rom, (char *) bios_fn, 0xc0000, 0x8000, 0x7fff, 0, MEM_MAPPING_EXTERNAL);
+    if (bios_fn != NULL)
+        {
+            if (info->local == S3_VIRGE_GX2)
+                rom_init(&virge->bios_rom, (char *) bios_fn, 0xc0000, 0x10000, 0xffff, 0, MEM_MAPPING_EXTERNAL);
+            else
+                rom_init(&virge->bios_rom, (char *) bios_fn, 0xc0000, 0x8000, 0x7fff, 0, MEM_MAPPING_EXTERNAL);
+        }
 
     mem_mapping_disable(&virge->bios_rom.mapping);