diff --git a/file_checker.go b/file_checker.go
index 7ff8792..183629a 100644
--- a/file_checker.go
+++ b/file_checker.go
@@ -45,7 +45,7 @@ func (c fileChecker) Check(f string) ([]urlResult, error) {
 	return rs, nil
 }
 
-func (c fileChecker) CheckMany(fs []string, rc chan fileResult) {
+func (c fileChecker) CheckMany(fs []string, rc chan<- fileResult) {
 	wg := sync.WaitGroup{}
 
 	for _, f := range fs {