diff --git a/test/src/unit-bon8.cpp b/test/src/unit-bon8.cpp
index ba9f9173f..6dd1f610f 100644
--- a/test/src/unit-bon8.cpp
+++ b/test/src/unit-bon8.cpp
@@ -215,7 +215,7 @@ TEST_CASE("BON8")
                 SECTION("-2147483649")
                 {
                     // cannot use -2147483649 directly, see https://developercommunity.visualstudio.com/t/-2147483648-c4146-error/141813#T-N229960
-                    json j = -2147483648 - 1;
+                    json j = std::int64_t(-2147483647) - 2;
                     std::vector<uint8_t> expected = {0x8D, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF};
                     const auto result = json::to_bon8(j);
                     CHECK(result == expected);