diff --git a/subscriptions.go b/subscriptions.go
index cd5fa46..6443306 100644
--- a/subscriptions.go
+++ b/subscriptions.go
@@ -4,16 +4,10 @@ import (
 	"time"
 )
 
-// NewEveryMsg is used by Every to create a new message. It contains the time
-// at which the timer finished.
-type NewEveryMsg func(time.Time) Msg
-
 // Every is a subscription that ticks with the system clock at the given
 // duration, similar to cron. It's particularly useful if you have several
 // subscriptions that need to run in sync.
-//
-// TODO: make it cancelable.
-func Every(duration time.Duration, newMsg NewEveryMsg) Sub {
+func Every(duration time.Duration, newMsg func(time.Time) Msg) Sub {
 	return func() Msg {
 		n := time.Now()
 		d := n.Truncate(duration).Add(duration).Sub(n)
@@ -27,9 +21,7 @@ func Every(duration time.Duration, newMsg NewEveryMsg) Sub {
 
 // Tick is a subscription that at an interval independent of the system clock
 // at the given duration. That is, it begins precisely when invoked.
-//
-// TODO: make it cancelable.
-func Tick(d time.Duration, newMsg NewEveryMsg) Sub {
+func Tick(d time.Duration, newMsg func(time.Time) Msg) Sub {
 	return func() Msg {
 		t := time.NewTimer(d)
 		select {