diff --git a/send.go b/send.go
index bda922d..2eaf1d5 100644
--- a/send.go
+++ b/send.go
@@ -68,7 +68,12 @@ func sendMachine(s string) error {
 			shell.RunRealtime([]string{"mv", "-f", "/usr/bin/zood", "/usr/bin/zood.last"})
 			shell.RunRealtime([]string{"apt", "update"})
 			shell.RunRealtime([]string{"apt", "install", "zood"})
-			shell.RunRealtime([]string{"rm", "-f", "/usr/bin/zood.last"})
+			if shell.Exists("/usr/bin/zood") {
+				shell.RunRealtime([]string{"rm", "-f", "/usr/bin/zood.last"})
+			} else {
+				// there is not a new version of the binary. move the old one back
+				shell.RunRealtime([]string{"mv", "-f", "/usr/bin/zood.last", "/usr/bin/zood"})
+			}
 			os.Exit(0)
 		} else if strings.HasPrefix(line, "apt install") {
 			log.Info("machine install", line)