diff --git a/lectures/03-goroutines/lecture.slide b/lectures/03-goroutines/lecture.slide
index 0ed54cf..a045bc1 100644
--- a/lectures/03-goroutines/lecture.slide
+++ b/lectures/03-goroutines/lecture.slide
@@ -361,8 +361,10 @@
   func Tick(d time.Duration) <-chan time.Time {
       ch := make(chan time.Time)
       go func() {
-          time.Sleep(d)
-          ch <- time.Now()
+          for {
+              time.Sleep(d)
+              ch <- time.Now()
+          }
       }()
       return ch
   }