diff --git a/core/installer/cluster.go b/core/installer/cluster.go
index a51435f..284e393 100644
--- a/core/installer/cluster.go
+++ b/core/installer/cluster.go
@@ -3,6 +3,7 @@
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -57,7 +58,7 @@
 	if resp.StatusCode != http.StatusOK {
 		var buf bytes.Buffer
 		io.Copy(&buf, resp.Body)
-		return fmt.Errorf(buf.String())
+		return errors.New(buf.String())
 	}
 	return nil
 }
@@ -78,7 +79,7 @@
 	if resp.StatusCode != http.StatusOK {
 		var buf bytes.Buffer
 		io.Copy(&buf, resp.Body)
-		return fmt.Errorf(buf.String())
+		return errors.New(buf.String())
 	}
 	return nil
 }