diff --git a/tests/libtest/lib1557.c b/tests/libtest/lib1557.c
index 2381c07b6a..0e33f48fbb 100644
--- a/tests/libtest/lib1557.c
+++ b/tests/libtest/lib1557.c
@@ -36,7 +36,7 @@ static CURLcode test_lib1557(const char *URL)
   global_init(CURL_GLOBAL_ALL);
 
   multi_init(curlm);
-  multi_setopt(curlm, CURLMOPT_MAX_HOST_CONNECTIONS, 1);
+  multi_setopt(curlm, CURLMOPT_MAX_HOST_CONNECTIONS, 1L);
 
   easy_init(curl1);
   easy_setopt(curl1, CURLOPT_URL, URL);