diff --git a/client/error.go b/client/error.go
index b6c61ea..5db98af 100644
--- a/client/error.go
+++ b/client/error.go
@@ -22,7 +22,7 @@ func getError(data []byte) (err error) {
 		err = fmt.Errorf("Not a error data: %V", data)
 		return
 	}
-	err = errors.New(fmt.Sprintf("%s: %s", rel[0], rel[1]))
+	err = fmt.Errorf("%s: %s", rel[0], rel[1])
 	return
 }
 
diff --git a/worker/error.go b/worker/error.go
index c25a6d3..28464c0 100644
--- a/worker/error.go
+++ b/worker/error.go
@@ -21,7 +21,7 @@ func getError(data []byte) (err error) {
 		err = fmt.Errorf("Not a error data: %V", data)
 		return
 	}
-	err = errors.New(fmt.Sprintf("%s: %s", rel[0], rel[1]))
+	err = fmt.Errorf("%s: %s", rel[0], rel[1])
 	return
 }