diff --git a/tars/registry/registry.go b/tars/registry/registry.go
index ea4c45bd..d4c24a5c 100644
--- a/tars/registry/registry.go
+++ b/tars/registry/registry.go
@@ -9,12 +9,12 @@ import (
 
 // ServantInstance is an instance of a service in a discovery system.
 type ServantInstance struct {
-	TarsVersion string            `json:"tarsVersion"`
+	TarsVersion string            `json:"tars_version"`
 	App         string            `json:"app"`
 	Server      string            `json:"server"`
 	Servant     string            `json:"servant"`
-	EnableSet   bool              `json:"enableSet"`
-	SetDivision string            `json:"setDivision"`
+	EnableSet   bool              `json:"enable_set"`
+	SetDivision string            `json:"set_division"`
 	Protocol    string            `json:"protocol"`
 	Endpoint    endpoint.Endpoint `json:"endpoint"`
 }