diff --git a/tests/aot/basic/string-item-isset.phpt b/tests/aot/basic/string-item-isset.phpt
new file mode 100644
index 00000000..c29c2119
--- /dev/null
+++ b/tests/aot/basic/string-item-isset.phpt
@@ -0,0 +1,18 @@
+--TEST--
+string item isset
+--FILE--
+<?php
+function main()
+{
+    $type = '?string';
+    var_dump(isset($type[0]));
+    var_dump(isset($type[6]));
+    var_dump(isset($type[10]));
+    var_dump(($type[0] ?? ''));
+}
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(false)
+string(1) "?"