diff --git a/cachetable.go b/cachetable.go
index b041bbd..b77cf23 100644
--- a/cachetable.go
+++ b/cachetable.go
@@ -48,9 +48,6 @@ func (table *CacheTable) Count() int {
 
 // Foreach all items
 func (table *CacheTable) Foreach(trans func(key interface{}, item *CacheItem)) {
-	table.RLock()
-	defer table.RUnlock()
-
 	for k, v := range table.items {
 		trans(k, v)
 	}
diff --git a/examples/concurrent-cache-manager/concurrent-cache-manager.go b/examples/concurrent-cache-manager/concurrent-cache-manager.go
new file mode 100644
index 0000000..85074cc
--- /dev/null
+++ b/examples/concurrent-cache-manager/concurrent-cache-manager.go
@@ -0,0 +1,34 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/muesli/cache2go"
+)
+
+func main() {
+	store := cache2go.Cache("test")
+	store.AddAboutToDeleteItemCallback(func(v *cache2go.CacheItem) {
+		fmt.Println("delete:", v)
+	})
+
+	key := "test1"
+	store.Add(key, time.Second*1800, "asdfasdfasd")
+	fmt.Println("fitst delete:")
+	store.Delete(key)
+
+	store.Add(key, time.Second*1800, "asdfasdfasd")
+
+	go func() {
+		time.Sleep(time.Second * 2)
+		fmt.Println("goroutine delete:")
+		store.Foreach(func(key interface{}, v *cache2go.CacheItem) {
+			fmt.Println("start")
+			store.Delete(key)
+			fmt.Println("end")
+		})
+	}()
+
+	time.Sleep(time.Second * 10)
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..dd9161d
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/muesli/cache2go
+
+go 1.15