diff --git a/composer.json b/composer.json
index 1b38710a..d1c290df 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
         "wp-cli/db-command": "^1.3 || ^2 || ^3",
         "wp-cli/entity-command": "^1.3 || ^2 || ^3",
         "wp-cli/extension-command": "^1.2 || ^2 || ^3",
-        "wp-cli/wp-cli-tests": "^5"
+        "wp-cli/wp-cli-tests": "dev-main#9298472990ea1237596345fd5cb8a37c53372495 as 5.1.99"
     },
     "config": {
         "process-timeout": 7200,