diff --git a/plugin/inner/interface.go b/plugin/inner/interface.go
new file mode 100644
index 00000000..ddaafec4
--- /dev/null
+++ b/plugin/inner/interface.go
@@ -0,0 +1,14 @@
+package pluginInternal
+
+// FuncCaller is the interface that we're exposing as a plugin.
+type FuncCaller interface {
+	GetNames() ([]string, error)                                    // get all plugin function names list
+	Call(funcName string, args ...interface{}) (interface{}, error) // call plugin function
+}
+
+type IPlugin interface {
+	Init(path string) error                                         // init plugin
+	Has(funcName string) bool                                       // check if plugin has function
+	Call(funcName string, args ...interface{}) (interface{}, error) // call function
+	Quit() error                                                    // quit plugin
+}
diff --git a/plugin/inner/host.go b/plugin/inner/rpc.go
similarity index 78%
rename from plugin/inner/host.go
rename to plugin/inner/rpc.go
index a8422a38..804bc5a3 100644
--- a/plugin/inner/host.go
+++ b/plugin/inner/rpc.go
@@ -18,12 +18,6 @@ type funcData struct {
 	Args []interface{} // function arguments
 }
 
-// FuncCaller is the interface that we're exposing as a plugin.
-type FuncCaller interface {
-	GetNames() ([]string, error)                                    // get all plugin function names list
-	Call(funcName string, args ...interface{}) (interface{}, error) // call plugin function
-}
-
 // functionRPC runs on the host side.
 type functionRPC struct {
 	client *rpc.Client
@@ -101,10 +95,3 @@ func (p *HRPPlugin) Server(*plugin.MuxBroker) (interface{}, error) {
 func (HRPPlugin) Client(b *plugin.MuxBroker, c *rpc.Client) (interface{}, error) {
 	return &functionRPC{client: c}, nil
 }
-
-type IPlugin interface {
-	Init(path string) error                                         // init plugin
-	Has(funcName string) bool                                       // check if plugin has function
-	Call(funcName string, args ...interface{}) (interface{}, error) // call function
-	Quit() error                                                    // quit plugin
-}