diff --git a/src/vid_vga.h b/src/vid_vga.h
index 3297d04b0..5ee66fc0b 100644
--- a/src/vid_vga.h
+++ b/src/vid_vga.h
@@ -2,4 +2,5 @@
    see COPYING for more details
 */
 extern device_t vga_device;
+extern device_t trigem_unk_device;
 extern device_t ps1vga_device;