diff --git a/core/discov/internal/listener.go b/core/discov/internal/listener.go
index 2f416d04..6340b1cb 100644
--- a/core/discov/internal/listener.go
+++ b/core/discov/internal/listener.go
@@ -1,4 +1,3 @@
-//go:generate mockgen -package internal -destination listener_mock.go -source listener.go Listener
 package internal
 
 type Listener interface {
diff --git a/core/discov/internal/listener_mock.go b/core/discov/internal/listener_mock.go
deleted file mode 100644
index 7e81e87b..00000000
--- a/core/discov/internal/listener_mock.go
+++ /dev/null
@@ -1,45 +0,0 @@
-// Code generated by MockGen. DO NOT EDIT.
-// Source: listener.go
-
-// Package internal is a generated GoMock package.
-package internal
-
-import (
-	gomock "github.com/golang/mock/gomock"
-	reflect "reflect"
-)
-
-// MockListener is a mock of Listener interface
-type MockListener struct {
-	ctrl     *gomock.Controller
-	recorder *MockListenerMockRecorder
-}
-
-// MockListenerMockRecorder is the mock recorder for MockListener
-type MockListenerMockRecorder struct {
-	mock *MockListener
-}
-
-// NewMockListener creates a new mock instance
-func NewMockListener(ctrl *gomock.Controller) *MockListener {
-	mock := &MockListener{ctrl: ctrl}
-	mock.recorder = &MockListenerMockRecorder{mock}
-	return mock
-}
-
-// EXPECT returns an object that allows the caller to indicate expected use
-func (m *MockListener) EXPECT() *MockListenerMockRecorder {
-	return m.recorder
-}
-
-// OnUpdate mocks base method
-func (m *MockListener) OnUpdate(keys, values []string, newKey string) {
-	m.ctrl.T.Helper()
-	m.ctrl.Call(m, "OnUpdate", keys, values, newKey)
-}
-
-// OnUpdate indicates an expected call of OnUpdate
-func (mr *MockListenerMockRecorder) OnUpdate(keys, values, newKey interface{}) *gomock.Call {
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "OnUpdate", reflect.TypeOf((*MockListener)(nil).OnUpdate), keys, values, newKey)
-}
diff --git a/core/discov/publisher_test.go b/core/discov/publisher_test.go
index d49a0a35..ab6d0aaa 100644
--- a/core/discov/publisher_test.go
+++ b/core/discov/publisher_test.go
@@ -111,6 +111,10 @@ func TestPublisher_keepAliveAsyncQuit(t *testing.T) {
 	defer ctrl.Finish()
 	const id clientv3.LeaseID = 1
 	cli := internal.NewMockEtcdClient(ctrl)
+	cli.EXPECT().ActiveConnection()
+	cli.EXPECT().Close()
+	defer cli.Close()
+	cli.ActiveConnection()
 	restore := setMockClient(cli)
 	defer restore()
 	cli.EXPECT().Ctx().AnyTimes()