diff --git a/function/function.go b/function/function.go
index 7112f3e..1ece80e 100644
--- a/function/function.go
+++ b/function/function.go
@@ -48,8 +48,8 @@ func (f Fn) Curry(i interface{}) func(...interface{}) interface{} {
 }
 
 // Compose compose the functions from right to left
-func Compose(fnList ...func(...string) string) func(...string) string {
-	return func(s... string) string {
+func Compose(fnList ...func(...interface{}) interface{}) func(...interface{}) interface{} {
+	return func(s... interface{}) interface{} {
 		f := fnList[0]
 		restFn := fnList[1:]
 
diff --git a/function/function_test.go b/function/function_test.go
index c934249..bed16d0 100644
--- a/function/function_test.go
+++ b/function/function_test.go
@@ -71,19 +71,17 @@ func TestCurry(t *testing.T) {
 }
 
 func TestCompose(t *testing.T) {
-	toUpper := func(a... string) string {
-		return strings.ToUpper(a[0])
+	toUpper := func(a ...interface{}) interface{} {
+		return strings.ToUpper(a[0].(string))
 	}
-
-	toLower := func(a... string) string {
-		return strings.ToLower(a[0])
+	toLower := func(a ...interface{}) interface{} {
+		return strings.ToLower(a[0].(string))
 	}
 
 	expect := toUpper(toLower("aBCde"))
 	cf := Compose(toUpper, toLower)
 	res := cf("aBCde")
 
-	fmt.Println(res, expect)
 	if res != expect {
 		t.FailNow()
 	}