diff --git a/src/device/input/parse/v01/transform.go b/src/device/input/parse/v01/transform.go
new file mode 100644
index 0000000..258deb9
--- /dev/null
+++ b/src/device/input/parse/v01/transform.go
@@ -0,0 +1,14 @@
+package v01
+
+type (
+	transformation map[string]string
+)
+
+func (t transformation) pipe(s string) string {
+	for i := range s {
+		if v := t[s[i:i+1]]; v != "" {
+			s = s[:i] + v[:1] + s[i+1:]
+		}
+	}
+	return s
+}
diff --git a/src/device/input/parse/v01/v01.go b/src/device/input/parse/v01/v01.go
index 916d35d..ec60583 100644
--- a/src/device/input/parse/v01/v01.go
+++ b/src/device/input/parse/v01/v01.go
@@ -40,10 +40,9 @@ type (
 			Message string
 		}
 		Players []struct {
-			Transformation v01Transformation
+			Transformation transformation
 		}
 	}
-	v01Transformation map[string]string
 )
 
 func NewV01(ctx context.Context, src raw.Raw) *V01 {
@@ -98,15 +97,6 @@ func (cfg v01Cfg) transform(msg v01Msg) v01Msg {
 	return msg
 }
 
-func (t v01Transformation) pipe(s string) string {
-	for i := range s {
-		if v := t[s[i:i+1]]; v != "" {
-			s = s[:i] + v[:1] + s[i+1:]
-		}
-	}
-	return s
-}
-
 func (v01 *V01) telemetry(msg v01Msg) {
 	if FlagDebug {
 		log.Printf("%s|%dms", msg.U, time.Now().UnixNano()/int64(time.Millisecond)-msg.T)
diff --git a/src/device/input/parse/v01/v01_test.go b/src/device/input/parse/v01/v01_test.go
index b81d3e1..c21ba70 100644
--- a/src/device/input/parse/v01/v01_test.go
+++ b/src/device/input/parse/v01/v01_test.go
@@ -42,7 +42,7 @@ func TestV01TransformationPipe(t *testing.T) {
 	for name, d := range cases {
 		c := d
 		t.Run(name, func(t *testing.T) {
-			got := v01Transformation(c.xform).pipe(c.input)
+			got := transformation(c.xform).pipe(c.input)
 			if got != c.want {
 				t.Errorf("%+v(%s) want %s got %s", c.xform, c.input, c.want, got)
 			}