diff --git a/2022/01/go_func1/Program.go b/2022/01/go_func1/Program.go
index 0decab3..b1873a2 100644
--- a/2022/01/go_func1/Program.go
+++ b/2022/01/go_func1/Program.go
@@ -12,7 +12,7 @@ func isEven(n int) bool {
 func main() {
 	fmt.Println("Hello World")
 	stream.Of(0, 1, 2, 3, 4).
-		Filter(func(n int) {
+		Filter(func(n int) bool {
 			return n%2 == 0
 		}).
 		ForEach(func(n int) {