--TEST-- The result of a by-ref function call can be yielded just fine --FILE-- <?php function &nop(&$var) { return $var; } function &gen(&$var) { yield nop($var); } $var = "foo"; $gen = gen($var); foreach ($gen as &$varRef) { $varRef = "bar"; } var_dump($var); ?> --EXPECT-- string(3) "bar"