diff --git a/composer.json b/composer.json
index 038735a..e0be328 100644
--- a/composer.json
+++ b/composer.json
@@ -37,7 +37,7 @@
         "ext-SimpleXML": "*",
         "ext-session": "*",
 
-        "beste/clock": "~3.0",
+        "beste/clock": "~4.0",
         "simplesamlphp/assert": "~2.0",
         "simplesamlphp/composer-module-installer": "~1.7",
         "simplesamlphp/simplesamlphp": "~2.5",