diff --git a/test/unit/util.c b/test/unit/util.c
index f4d9f33..af9e90c 100644
--- a/test/unit/util.c
+++ b/test/unit/util.c
@@ -100,11 +100,19 @@ void test_unit(void) {
   ntp_ts.hi = htonl(JAN_1970);
   ntp_ts.lo = 0xffffffff;
   UTI_Ntp64ToTimespec(&ntp_ts, &ts);
+#if defined(HAVE_LONG_TIME_T) && NTP_ERA_SPLIT > 0
+  TEST_CHECK(ts.tv_sec == 0x100000000LL * (1 + (NTP_ERA_SPLIT - 1) / 0x100000000LL));
+#else
   TEST_CHECK(ts.tv_sec == 0);
+#endif
   TEST_CHECK(ts.tv_nsec == 999999999);
 
   UTI_AddDoubleToTimespec(&ts, 1e-9, &ts);
+#if defined(HAVE_LONG_TIME_T) && NTP_ERA_SPLIT > 0
+  TEST_CHECK(ts.tv_sec == 1 + 0x100000000LL * (1 + (NTP_ERA_SPLIT - 1) / 0x100000000LL));
+#else
   TEST_CHECK(ts.tv_sec == 1);
+#endif
   TEST_CHECK(ts.tv_nsec == 0);
 
   ntp_fuzz.hi = 0;