diff --git a/batch_consumer_test.go b/batch_consumer_test.go
index 8c1349a..5c5d950 100644
--- a/batch_consumer_test.go
+++ b/batch_consumer_test.go
@@ -15,12 +15,14 @@ func Test_batchConsumer_startBatch(t *testing.T) {
 	// Given
 	var numberOfBatch int
 
+	mc := mockReader{}
 	bc := batchConsumer{
 		base: &base{
 			messageCh:            make(chan *Message),
 			metric:               &ConsumerMetric{},
 			wg:                   sync.WaitGroup{},
 			messageGroupDuration: 500 * time.Millisecond,
+			r:                    &mc,
 		},
 		messageGroupLimit: 3,
 		consumeFn: func(messages []*Message) error {
diff --git a/consumer_base_test.go b/consumer_base_test.go
index 5e22956..63ef367 100644
--- a/consumer_base_test.go
+++ b/consumer_base_test.go
@@ -92,9 +92,15 @@ func (m *mockReader) FetchMessage(ctx context.Context) (*kafka.Message, error) {
 }
 
 func (m *mockReader) Close() error {
-	panic("implement me")
+	if m.wantErr {
+		return errors.New("err")
+	}
+	return nil
 }
 
 func (m *mockReader) CommitMessages(messages []kafka.Message) error {
-	panic("implement me")
+	if m.wantErr {
+		return errors.New("err")
+	}
+	return nil
 }