diff --git a/ants_test.go b/ants_test.go
index 44f013e..913a6a6 100644
--- a/ants_test.go
+++ b/ants_test.go
@@ -105,7 +105,6 @@ func TestCodeCov(t *testing.T) {
 	t.Logf("pool with func, free workers number:%d", p.Free())
 	p.ReSize(AntsSize / 2)
 	t.Logf("pool with func, after resize, capacity:%d", p.Cap())
-
 }
 
 // func TestNoPool(t *testing.T) {
diff --git a/pool.go b/pool.go
index cd10d2a..c832c9b 100644
--- a/pool.go
+++ b/pool.go
@@ -145,10 +145,12 @@ func (p *Pool) Release() error {
 		for i := 0; i < running; i++ {
 			p.getWorker().task <- nil
 		}
+		p.lock.Lock()
 		for i := range p.workers {
 			p.workers[i] = nil
 		}
 		p.workers = nil
+		p.lock.Unlock()
 	})
 	return nil
 }
diff --git a/pool_func.go b/pool_func.go
index bd85f03..7040f83 100644
--- a/pool_func.go
+++ b/pool_func.go
@@ -150,10 +150,12 @@ func (p *PoolWithFunc) Release() error {
 		for i := 0; i < running; i++ {
 			p.getWorker().args <- nil
 		}
+		p.lock.Lock()
 		for i := range p.workers {
 			p.workers[i] = nil
 		}
 		p.workers = nil
+		p.lock.Unlock()
 	})
 	return nil
 }