Add cast to silence (harmless) conversion warning.
diff --git a/test/unit/tsd.c b/test/unit/tsd.c
index 4e2622a..d5f96ac 100644
--- a/test/unit/tsd.c
+++ b/test/unit/tsd.c
@@ -79,7 +79,7 @@
 TEST_BEGIN(test_tsd_main_thread)
 {
 
-	thd_start((void *) 0xa5f3e329);
+	thd_start((void *)(uintptr_t)0xa5f3e329);
 }
 TEST_END