diff --git a/composer.json b/composer.json
index 86a315e..f3e4c7e 100644
--- a/composer.json
+++ b/composer.json
@@ -21,7 +21,7 @@
         "ergebnis/composer-normalize": "^2.7",
         "hamcrest/hamcrest-php": "^2.0",
         "madewithlove/license-checker": "^0.10.0 || ^1.0",
-        "mockery/mockery": "^1.4",
+        "mockery/mockery": "1.4.x-dev",
         "pds/skeleton": "^1.0",
         "phly/keep-a-changelog": "^2.9",
         "php-parallel-lint/php-console-highlighter": "^0.5.0",