diff --git a/include/c128.h b/include/c128.h
index 37a813f8c..47fbb26b1 100644
--- a/include/c128.h
+++ b/include/c128.h
@@ -102,7 +102,7 @@
 
 
 
-unsigned char __fastcall__ videomode (unsigned char Mode);
+unsigned __fastcall__ videomode (unsigned Mode);
 /* Set the video mode, return the old mode. Call with one of the VIDEOMODE_xx
  * constants.
  */