diff --git a/runtime/runtime.go b/runtime/runtime.go
index 567e8c3b..62813973 100644
--- a/runtime/runtime.go
+++ b/runtime/runtime.go
@@ -12,6 +12,7 @@ var (
 	// DefaultName is default runtime service name
 	DefaultName = "go.micro.runtime"
 
+	ErrNotFound      = errors.New("not found")
 	ErrAlreadyExists = errors.New("already exists")
 )