diff --git a/stubs/CoreImmutableClasses.phpstub b/stubs/CoreImmutableClasses.phpstub
index 23eb77bdb77..91c0a41c69c 100644
--- a/stubs/CoreImmutableClasses.phpstub
+++ b/stubs/CoreImmutableClasses.phpstub
@@ -58,10 +58,8 @@ class DateTimeImmutable implements DateTimeInterface
 
     /**
      * @psalm-mutation-free
-     * @return static|false this method can fail in case an {@see DateInterval} with relative
-     *                      week days is passed in.
-     *
-     * @see https://github.com/php/php-src/blob/534127d3b22b193ffb9511c4447584f0d2bd4e24/ext/date/php_date.c#L3157-L3160
+     * @return static
+
      */
     public function sub(DateInterval $interval) {}
 
diff --git a/tests/MethodCallTest.php b/tests/MethodCallTest.php
index cb3103fdeb8..377a3737805 100644
--- a/tests/MethodCallTest.php
+++ b/tests/MethodCallTest.php
@@ -271,7 +271,7 @@ final class MyDate extends DateTimeImmutable {}
 
                     $b = (new DateTimeImmutable())->modify("+3 hours");',
                 'assertions' => [
-                    '$yesterday' => 'MyDate|false',
+                    '$yesterday' => 'MyDate',
                     '$b' => 'DateTimeImmutable',
                 ],
             ],