diff --git a/vlib/v/slow_tests/valgrind/1.strings_and_arrays.v b/vlib/v/slow_tests/valgrind/1.strings_and_arrays.v
index 4741ae4fbf..7b48049607 100644
--- a/vlib/v/slow_tests/valgrind/1.strings_and_arrays.v
+++ b/vlib/v/slow_tests/valgrind/1.strings_and_arrays.v
@@ -398,6 +398,7 @@ fn advanced_options() {
 	s2 := parse_header1('foo:bar') or { return }
 	_ := s.len + s2.len // avoid warning for unused variables
 	// TODO: fix -autofree, so that it adds this free automatically:
+	unsafe { s.free() }
 	unsafe { s2.free() }
 }