diff --git a/pool.go b/pool.go
index 36fe5cb..4c7309f 100644
--- a/pool.go
+++ b/pool.go
@@ -62,6 +62,8 @@ type Pool struct {
 // clear expired workers periodically.
 func (p *Pool) periodicallyPurge() {
 	heartbeat := time.NewTicker(p.expiryDuration)
+	defer heartbeat.Stop()
+
 	for range heartbeat.C {
 		currentTime := time.Now()
 		p.lock.Lock()
diff --git a/pool_func.go b/pool_func.go
index fbcbe9d..5c46689 100644
--- a/pool_func.go
+++ b/pool_func.go
@@ -63,6 +63,8 @@ type PoolWithFunc struct {
 // clear expired workers periodically.
 func (p *PoolWithFunc) periodicallyPurge() {
 	heartbeat := time.NewTicker(p.expiryDuration)
+	defer heartbeat.Stop()
+
 	for range heartbeat.C {
 		currentTime := time.Now()
 		p.lock.Lock()