diff --git a/cache/vars.go b/cache/vars.go
index 9324d81..42a719b 100644
--- a/cache/vars.go
+++ b/cache/vars.go
@@ -42,10 +42,13 @@ func (c *VarCache[T]) IsExpired() bool {
 }
 
 func (c *VarCache[T]) Flush() {
-	mu := c.v.Load().mutex
+	v := c.v.Load()
+	mu := v.mutex
 	mu.Lock()
 	defer mu.Unlock()
-	c.v.Delete()
+	var vv T
+	v.data = vv
+	c.v.Store(v)
 }
 
 func (c *VarCache[T]) GetCache(ctx context.Context, timeout time.Duration, params ...any) (T, error) {
diff --git a/cache/vars_test.go b/cache/vars_test.go
new file mode 100644
index 0000000..846f7f6
--- /dev/null
+++ b/cache/vars_test.go
@@ -0,0 +1,66 @@
+package cache
+
+import (
+	"context"
+	"fmt"
+	"testing"
+	"time"
+)
+
+var cc = *NewVarCache(func(a ...any) (int, error) {
+	return 1, nil
+}, time.Minute)
+
+func TestVarCache_Flush(t *testing.T) {
+	type testCase[T any] struct {
+		name string
+		c    VarCache[T]
+	}
+	tests := []testCase[int]{
+		{
+			name: "1",
+			c:    cc,
+		},
+	}
+	c := context.Background()
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			fmt.Println(tt.c.GetCache(c, time.Second))
+			tt.c.Flush()
+			fmt.Println(tt.c.GetCache(c, time.Second))
+		})
+	}
+}
+
+func TestVarCache_IsExpired(t *testing.T) {
+	type testCase[T any] struct {
+		name string
+		c    VarCache[T]
+		want bool
+	}
+	tests := []testCase[int]{
+		{
+			name: "expired",
+			c:    cc,
+			want: true,
+		},
+		{
+			name: "not expired",
+			c: func() VarCache[int] {
+				v := *NewVarCache(func(a ...any) (int, error) {
+					return 1, nil
+				}, time.Minute)
+				_, _ = v.GetCache(context.Background(), time.Second)
+				return v
+			}(),
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.c.IsExpired(); got != tt.want {
+				t.Errorf("IsExpired() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}