diff --git a/tests/io_test.cpp b/tests/io_test.cpp
index a53229e..a15fb59 100644
--- a/tests/io_test.cpp
+++ b/tests/io_test.cpp
@@ -35,6 +35,8 @@ int main() {
     }
     cancel_thread.join();
     assert(scopes_continue.count == -1);
+    auto lock = scopes_continue.shared_lock();
+    assert(!lock);
 
     scopes_continue.count = 0;