diff --git a/bin/validate-json b/bin/validate-json
index 2f2fe448..e93d53a0 100755
--- a/bin/validate-json
+++ b/bin/validate-json
@@ -218,7 +218,8 @@ $refResolver = new JsonSchema\RefResolver($retriever);
 $refResolver->resolve($schema, $urlSchema);
 
 if (isset($arOptions['--dump-schema'])) {
-    echo json_encode($schema, JSON_PRETTY_PRINT) . "\n";
+    $options = defined('JSON_PRETTY_PRINT') ? JSON_PRETTY_PRINT : 0;
+    echo json_encode($schema, $options) . "\n";
     exit();
 }