diff --git a/test/unit/tsd.c b/test/unit/tsd.c
index 4e2622a3..d5f96ac3 100644
--- a/test/unit/tsd.c
+++ b/test/unit/tsd.c
@@ -79,7 +79,7 @@ thd_start(void *arg)
 TEST_BEGIN(test_tsd_main_thread)
 {
 
-	thd_start((void *) 0xa5f3e329);
+	thd_start((void *)(uintptr_t)0xa5f3e329);
 }
 TEST_END