diff --git a/client.go b/client.go
index 768135c..3a5de24 100644
--- a/client.go
+++ b/client.go
@@ -178,6 +178,9 @@ func (d processInOption) Value() interface{} { return time.Duration(d) }
 // ErrDuplicateTask error only applies to tasks enqueued with a Unique option.
 var ErrDuplicateTask = errors.New("task already exists")
 
+// ErrEmptyTypeTask indicates that task's typename is not specified.
+var ErrEmptyTypeTask = errors.New("task typename not specified")
+
 type option struct {
 	retry     int
 	queue     string
@@ -266,6 +269,9 @@ func (c *Client) Close() error {
 //
 // If no ProcessAt or ProcessIn options are provided, the task will be pending immediately.
 func (c *Client) Enqueue(task *Task, opts ...Option) (*TaskInfo, error) {
+	if task.Type() == "" {
+		return nil, fmt.Errorf("%w", ErrEmptyTypeTask)
+	}
 	c.mu.Lock()
 	if defaults, ok := c.opts[task.Type()]; ok {
 		opts = append(defaults, opts...)
diff --git a/client_test.go b/client_test.go
index 5a50a2f..3517af1 100644
--- a/client_test.go
+++ b/client_test.go
@@ -585,6 +585,11 @@ func TestClientEnqueueError(t *testing.T) {
 				Queue(""),
 			},
 		},
+		{
+			desc: "With empty task typename",
+			task: NewTask("", h.JSON(map[string]interface{}{})),
+			opts: []Option{},
+		},
 	}
 
 	for _, tc := range tests {