diff --git a/deploy.php b/deploy.php
index 8bb0d99..6bbf273 100644
--- a/deploy.php
+++ b/deploy.php
@@ -2,6 +2,13 @@
 
 namespace Deployer;
 
+use RuntimeException;
+
+$version = ltrim(Deployer::get()->getConsole()->getVersion(), 'v');
+if (6 !== (int) $version) {
+    throw new RuntimeException('YDeploy 1.x requires Deployer 6.x, but Deployer '.$version.' is used');
+}
+
 /** @psalm-suppress MissingFile */
 require 'recipe/common.php';