diff --git a/parallel.go b/parallel.go
index f678354..c058a8e 100644
--- a/parallel.go
+++ b/parallel.go
@@ -101,6 +101,8 @@ func (p *Parallel) secure(pipe *Pipeline) {
 			}
 			if p.exception != nil {
 				p.exception.OnExcept(err)
+			}else {
+				panic(err)
 			}
 		}
 		p.wg.Done()