diff --git a/basicstopwatch.go b/basicstopwatch.go
old mode 100644
new mode 100755
diff --git a/basictimer.go b/basictimer.go
old mode 100644
new mode 100755
diff --git a/config.go b/config.go
old mode 100644
new mode 100755
diff --git a/keyboard.go b/keyboard.go
old mode 100644
new mode 100755
diff --git a/keyboard_test.go b/keyboard_test.go
old mode 100644
new mode 100755
diff --git a/main.go b/main.go
old mode 100644
new mode 100755
diff --git a/tickprinter.go b/tickprinter.go
old mode 100644
new mode 100755
diff --git a/tickprinter_test.go b/tickprinter_test.go
old mode 100644
new mode 100755
diff --git a/timer.go b/timer.go
old mode 100644
new mode 100755
index 69bb71d..47a90fa
--- a/timer.go
+++ b/timer.go
@@ -1,17 +1,21 @@
 package main
 
 import (
+	"fmt"
 	"time"
+
+	"github.com/everdev/mack"
 )
 
 type Typed func(*Timer) string
 
 type Timer struct {
-	config Config
-	From   time.Time
-	Typed  Typed
-	paused bool
-	offset time.Duration
+	config    Config
+	From      time.Time
+	Typed     Typed
+	paused    bool
+	offset    time.Duration
+	displayed bool
 }
 
 func NewTimer(config Config) (*Timer, error) {
@@ -61,7 +65,17 @@ func (t *Timer) setTyped(config Config) error {
 }
 
 func (t *Timer) Remaining() time.Duration {
-	return time.Until(t.Deadline()) + time.Second
+	remaining := time.Until(t.Deadline()) + time.Second
+	if remaining < 0 && !t.displayed {
+		t.displayed = true
+		go func() {
+			_, err := mack.Alert(fmt.Sprintf("Timer for %s done", t.config.Msg))
+			if err == nil {
+				t.Ack()
+			}
+		}()
+	}
+	return remaining
 }
 
 func (t *Timer) Deadline() time.Time {
@@ -76,9 +90,11 @@ func (t *Timer) Ack() {
 	for t.Done() {
 		t.From = t.From.Add(t.config.Duration)
 	}
+	t.displayed = false
 }
 
 func (t *Timer) Reset() {
+	t.Ack()
 	t.From = time.Now()
 }
 
diff --git a/with.go b/with.go
old mode 100644
new mode 100755