diff --git a/lib/setuplib.php b/lib/setuplib.php
index 4468ce39790..d76545fe8ed 100644
--- a/lib/setuplib.php
+++ b/lib/setuplib.php
@@ -367,7 +367,7 @@ function get_whoops(): ?\Whoops\Run {
         return null;
     }
 
-    if (!$CFG->debug_developer_use_pretty_exceptions) {
+    if (empty($CFG->debug_developer_use_pretty_exceptions)) {
         return null;
     }