diff --git a/api/client_test.go b/api/client_test.go
index 2a1061b..8fae00e 100644
--- a/api/client_test.go
+++ b/api/client_test.go
@@ -2,8 +2,30 @@ package api
 
 import (
 	"testing"
+
+	"github.com/eosswedenorg/thalos/api/message"
 )
 
+type mockReader struct{}
+
+func (m mockReader) Read(channel Channel) ([]byte, error) {
+	return []byte{}, nil
+}
+
+func (m mockReader) Close() error {
+	return nil
+}
+
+func mockDecoder([]byte, any) error {
+	return nil
+}
+
+func mockHbHandler(message.HeartBeat) {
+}
+
+func mockActionHandler(message.ActionTrace) {
+}
+
 func TestClient_Subscribe(t *testing.T) {
 	tests := []struct {
 		name    string
@@ -17,7 +39,9 @@ func TestClient_Subscribe(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			c := Client{}
+			c := NewClient(&mockReader{}, mockDecoder)
+			c.OnHeartbeat = mockHbHandler
+			c.OnAction = mockActionHandler
 			if err := c.Subscribe(tt.channel); (err != nil) != tt.wantErr {
 				t.Errorf("Client.Subscribe() error = %v, wantErr %v", err, tt.wantErr)
 			}