diff --git a/go4k/cmd/asmfmt/main.go b/go4k/cmd/asmfmt/main.go
new file mode 100644
index 0000000..858f8d8
--- /dev/null
+++ b/go4k/cmd/asmfmt/main.go
@@ -0,0 +1,84 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"path/filepath"
+
+	"github.com/vsariola/sointu/go4k"
+)
+
+func main() {
+	write := flag.Bool("w", false, "Do not print reformatted asm songs to standard output. If a file's formatting is different from asmfmt's, overwrite it with asmfmt's version.")
+	list := flag.Bool("l", false, "Do not print reformatted asm songs to standard output, just list the filenames that reformatting changes.")
+	help := flag.Bool("h", false, "show help")
+	flag.Usage = printUsage
+	flag.Parse()
+	if flag.NArg() == 0 || *help {
+		flag.Usage()
+		os.Exit(0)
+	}
+	process := func(filename string) error {
+		origCodeBytes, err := ioutil.ReadFile(filename)
+		if err != nil {
+			return fmt.Errorf("could not read the file (%v)", err)
+		}
+		origCode := string(origCodeBytes)
+		song, err := go4k.DeserializeAsm(origCode)
+		if err != nil {
+			return fmt.Errorf("could not parse the file (%v)", err)
+		}
+		formattedCode, err := go4k.SerializeAsm(song)
+		if err != nil {
+			return fmt.Errorf("could not reformat the file (%v)", err)
+		}
+		if *write {
+			if formattedCode != origCode {
+				err := ioutil.WriteFile(filename, []byte(formattedCode), 0644)
+				if err != nil {
+					return fmt.Errorf("could write to file (%v)", err)
+				}
+			}
+		}
+		if *list {
+			if formattedCode != origCode {
+				fmt.Println(filename)
+			}
+		} else if !*write {
+			fmt.Print(formattedCode)
+		}
+		return nil
+	}
+	retval := 0
+	for _, param := range flag.Args() {
+		if info, err := os.Stat(param); err == nil && info.IsDir() {
+			files, err := filepath.Glob(path.Join(param, "*.asm"))
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "could not glob the path %v\n", param)
+				continue
+			}
+			for _, file := range files {
+				err := process(file)
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "%v: %v\n", file, err)
+					retval = 1
+				}
+			}
+		} else {
+			err := process(param)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "%v: %v\n", param, err)
+				retval = 1
+			}
+		}
+	}
+	os.Exit(retval)
+}
+
+func printUsage() {
+	fmt.Fprintf(os.Stderr, "Usage: %s [flags] [path ...]\n", os.Args[0])
+	flag.PrintDefaults()
+}