diff --git a/build/gen_stub.php b/build/gen_stub.php
index 4a293972f04ce..57424ac33aa91 100755
--- a/build/gen_stub.php
+++ b/build/gen_stub.php
@@ -2235,7 +2235,7 @@ public function __clone()
 
 class EvaluatedValue
 {
-    public /* readonly */ mixed $value;
+    public /* readonly */ /* mixed */ $value;
     public SimpleType $type;
     public Expr $expr;
     public bool $isUnknownConstValue;