--- supermin-5.2.1.orig/src/format_ext2_kernel.ml
+++ supermin-5.2.1/src/format_ext2_kernel.ml
@@ -213,6 +213,16 @@ and get_kernel_version debug kernel_file
   | None ->
      (* Try to work it out from the filename instead. *)
      let basename = Filename.basename kernel_file in
+     let basename =
+       let len = String.length basename in
+       if Filename.check_suffix basename ".xz" || Filename.check_suffix basename ".gz"
+       then (
+         let basename = String.sub basename 0 (len-3) in
+         basename
+       )
+       else (
+         basename
+       ) in
      if string_prefix "vmlinuz-" basename || string_prefix "vmlinux-" basename
      then (
        let version = String.sub basename 8 (String.length basename - 8) in