diff --git a/dlls/wininet/tests/http.c b/dlls/wininet/tests/http.c
index 9c2b949cdd2..8f3d02e664a 100644
--- a/dlls/wininet/tests/http.c
+++ b/dlls/wininet/tests/http.c
@@ -5551,7 +5551,7 @@ static void test_http_read(int port)
 
     send_response_len_and_wait(20000, TRUE, &ib);
     avail = expect_data_available(req.request, -1);
-    ok(avail < 17000, "avail = %u\n", avail);
+    ok(avail <= 20000, "avail = %u\n", avail);
 
     SET_WINE_ALLOW(INTERNET_STATUS_CLOSING_CONNECTION);
     SET_WINE_ALLOW(INTERNET_STATUS_CONNECTION_CLOSED);