diff --git a/set.go b/set.go
index 26882a7..879527a 100644
--- a/set.go
+++ b/set.go
@@ -23,7 +23,7 @@ func (set *Set) Delete(value interface{}) {
   delete(set.elements, value)
 }
 
-func (set *Set) List() []interface {
+func (set *Set) List() []interface{} {
   keys := make([]interface{}, 0, len(set.elements))
   for key := range set.elements {
     keys = append(keys, key)