diff --git a/installer.go b/installer.go
index caea329..005864a 100644
--- a/installer.go
+++ b/installer.go
@@ -30,7 +30,7 @@ func (i *Installer) Install(capFile *os.File, overwriteApplet bool) (err error)
 	cmdSet := globalplatform.NewCommandSet(i.c)
 
 	logger.Info("select ISD")
-	isd, err := cmdSet.Select()
+	err := cmdSet.Select()
 	if err != nil {
 		logger.Error("select failed", "error", err)
 		return err