diff --git a/pkg/config/file_source.go b/pkg/config/file_source.go
index 962026e1adf540afaec0e1273664c5786ba9dbea..444386199479b4b6849717ac617a2359464dae16 100644
--- a/pkg/config/file_source.go
+++ b/pkg/config/file_source.go
@@ -91,6 +91,8 @@ func (fs *FileSource) Close() {
 }
 
 func (fs *FileSource) SetEventHandler(eh EventHandler) {
+	fs.RWMutex.Lock()
+	defer fs.RWMutex.Unlock()
 	fs.configRefresher.eh = eh
 }
 
diff --git a/pkg/config/refresher.go b/pkg/config/refresher.go
index 4b49796fd3c7cf2faceba8779930867285c056f2..7a7f48a248039e904000908aa6879f4e1e43226f 100644
--- a/pkg/config/refresher.go
+++ b/pkg/config/refresher.go
@@ -86,7 +86,7 @@ func (r *refresher) fireEvents(name string, source, target map[string]string) er
 		log.Warn("generating event error", zap.Error(err))
 		return err
 	}
-	//Generate OnEvent Callback based on the events created
+	// Generate OnEvent Callback based on the events created
 	if r.eh != nil {
 		for _, e := range events {
 			r.eh.OnEvent(e)