diff --git a/config/http_config.go b/config/http_config.go
index c89f5864..3e320134 100644
--- a/config/http_config.go
+++ b/config/http_config.go
@@ -323,7 +323,7 @@ type HTTPClientConfig struct {
 	ProxyConfig `yaml:",inline"`
 	// HTTPHeaders specify headers to inject in the requests. Those headers
 	// could be marshalled back to the users.
-	HTTPHeaders *Headers `yaml:"http_headers" json:"http_headers"`
+	HTTPHeaders *Headers `yaml:"http_headers,omitempty" json:"http_headers,omitempty"`
 }
 
 // SetDirectory joins any relative file paths with dir.