diff --git a/buildroot-v86/board/v86/rootfs_overlay/root/opt/codemirror/codemirror b/buildroot-v86/board/v86/rootfs_overlay/root/opt/codemirror/codemirror
index 86fe090..cac9e04 100755
--- a/buildroot-v86/board/v86/rootfs_overlay/root/opt/codemirror/codemirror
+++ b/buildroot-v86/board/v86/rootfs_overlay/root/opt/codemirror/codemirror
@@ -1,4 +1,6 @@
 #!/bin/sh
+test -n "$1" || { echo "usage: codemirror <file>"; exit 0;  }
+
 me="$(dirname $(readlink -f $0))"
 file="$(readlink -f "$1")"
 
diff --git a/dist/v86-linux.iso b/dist/v86-linux.iso
index 896aae9..69479a6 100644
Binary files a/dist/v86-linux.iso and b/dist/v86-linux.iso differ