diff --git a/test/msgpack_cpp11.cpp b/test/msgpack_cpp11.cpp
index d69af910..e266da04 100644
--- a/test/msgpack_cpp11.cpp
+++ b/test/msgpack_cpp11.cpp
@@ -1082,7 +1082,7 @@ TEST(MSGPACK_TIMESPEC, timespec_object_with_zone_zero)
 TEST(MSGPACK_TIMESPEC, timespec_pack_convert_32bit_sec)
 {
     std::stringstream ss;
-    timespec val1{ 0xffffffffUL, 0 };
+    timespec val1{ std::numeric_limits<decltype(std::declval<timespec>().tv_sec)>::is_signed ? INT32_MAX : UINT32_MAX, 0 };
 
     msgpack::pack(ss, val1);
     std::string const& str = ss.str();
@@ -1098,7 +1098,7 @@ TEST(MSGPACK_TIMESPEC, timespec_pack_convert_32bit_sec)
 TEST(MSGPACK_TIMESPEC, timespec_object_with_zone_32bit_sec)
 {
     msgpack::zone z;
-    timespec val1{ 0xffffffffUL, 0 };
+    timespec val1{ std::numeric_limits<decltype(std::declval<timespec>().tv_sec)>::is_signed ? INT32_MAX : UINT32_MAX, 0 };
     msgpack::object obj(val1, z);
     timespec val2 = obj.as<timespec>();
     EXPECT_EQ(val1.tv_sec, val2.tv_sec);