diff --git a/composer.json b/composer.json
index 993811c..c0a1574 100644
--- a/composer.json
+++ b/composer.json
@@ -31,7 +31,7 @@
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^2.14",
-        "monolog/monolog": "^2.1",
+        "monolog/monolog": "^1.24|^2.1",
         "symfony/phpunit-bridge": "^4.2.3"
     },
     "suggest": {