diff --git a/composer.json b/composer.json
index dcc16c4301cbaa68fe7cb96e4d11cf1692ef94c9..a1169db0ae38187f35b28ae0acfe52a22ba32fab 100644
--- a/composer.json
+++ b/composer.json
@@ -16,6 +16,7 @@
         "paragonie/random_compat": "^1.0|^2.0"
     },
     "require-dev": {
+        "elasticsearch/elasticsearch": "^6.0",
         "phpunit/phpunit": "^6.0",
         "squizlabs/php_codesniffer": "^3.0",
         "satooshi/php-coveralls": "^2.0"