diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index fbf14c1..d64bc48 100755
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -1964,6 +1964,7 @@
       ASSERT_EQ(0, result);
     }
     int mask = arg->data->finished_mask.fetch_or(1 << arg->id);
+    mask |= 1 << arg->id;
     if (mask == ((1 << arg->data->thread_count) - 1)) {
       ASSERT_EQ(1, arg->data->serial_thread_count);
       arg->data->finished_iteration_count++;