diff --git a/test/unit/util.c b/test/unit/util.c
new file mode 100644
index 0000000..4637e7e
--- /dev/null
+++ b/test/unit/util.c
@@ -0,0 +1,140 @@
+#include <util.c>
+#include "test.h"
+
+void test_unit(void) {
+  NTP_int64 ntp_ts, ntp_fuzz;
+  struct timespec ts, ts2;
+  double x, y;
+  Float f;
+  int i, j, c;
+  char buf[16];
+
+  for (i = -31; i < 31; i++) {
+    x = pow(2.0, i);
+    y = UTI_Log2ToDouble(i);
+    TEST_CHECK(y / x > 0.99999 && y / x < 1.00001);
+  }
+
+  for (i = -89; i < 63; i++) {
+    x = pow(2.0, i);
+    y = UTI_FloatNetworkToHost(UTI_FloatHostToNetwork(x));
+    TEST_CHECK(y / x > 0.99999 && y / x < 1.00001);
+  }
+
+  for (i = 0; i < 100000; i++) {
+    x = TST_GetRandomDouble(-1000.0, 1000.0);
+    y = UTI_FloatNetworkToHost(UTI_FloatHostToNetwork(x));
+    TEST_CHECK(y / x > 0.99999 && y / x < 1.00001);
+
+    UTI_GetRandomBytes(&f, sizeof (f));
+    x = UTI_FloatNetworkToHost(f);
+    TEST_CHECK(x > 0.0 || x <= 0.0);
+  }
+
+  TEST_CHECK(UTI_DoubleToNtp32(1.0) == htonl(65536));
+  TEST_CHECK(UTI_DoubleToNtp32(0.0) == htonl(0));
+  TEST_CHECK(UTI_DoubleToNtp32(1.0 / (65536.0)) == htonl(1));
+  TEST_CHECK(UTI_DoubleToNtp32(1.000001 / (65536.0)) == htonl(2));
+  TEST_CHECK(UTI_DoubleToNtp32(1.000001) == htonl(65537));
+  TEST_CHECK(UTI_DoubleToNtp32(1000000) == htonl(0xffffffff));
+  TEST_CHECK(UTI_DoubleToNtp32(-1.0) == htonl(0));
+
+  ntp_ts.hi = htonl(JAN_1970);
+  ntp_ts.lo = 0xffffffff;
+  UTI_Ntp64ToTimespec(&ntp_ts, &ts);
+  TEST_CHECK(ts.tv_sec == 1);
+  TEST_CHECK(ts.tv_nsec == 0);
+
+  ntp_fuzz.hi = 0;
+  ntp_fuzz.lo = htonl(0xff1234ff);
+
+  UTI_TimespecToNtp64(&ts, &ntp_ts, &ntp_fuzz);
+  TEST_CHECK(ntp_ts.hi == htonl(JAN_1970 + 1));
+  TEST_CHECK(ntp_ts.lo == ntp_fuzz.lo);
+
+  ts.tv_sec = ts.tv_nsec = 0;
+  UTI_TimespecToNtp64(&ts, &ntp_ts, &ntp_fuzz);
+  TEST_CHECK(ntp_ts.hi == 0);
+  TEST_CHECK(ntp_ts.lo == 0);
+
+  TEST_CHECK(UTI_IsZeroTimespec(&ts));
+  TEST_CHECK(UTI_IsZeroNtp64(&ntp_ts));
+
+  ts.tv_sec = 1;
+  ntp_ts.hi = htonl(1);
+
+  TEST_CHECK(!UTI_IsZeroTimespec(&ts));
+  TEST_CHECK(!UTI_IsZeroNtp64(&ntp_ts));
+
+  ts.tv_sec = 0;
+  ntp_ts.hi = 0;
+  ts.tv_nsec = 1;
+  ntp_ts.lo = htonl(1);
+
+  TEST_CHECK(!UTI_IsZeroTimespec(&ts));
+  TEST_CHECK(!UTI_IsZeroNtp64(&ntp_ts));
+
+  ntp_fuzz.hi = htonl(1);
+  ntp_fuzz.lo = htonl(3);
+  ntp_ts.hi = htonl(1);
+  ntp_ts.lo = htonl(2);
+
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_ts) == 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_fuzz) < 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_fuzz, &ntp_ts) > 0);
+
+  ntp_ts.hi = htonl(0x80000002);
+  ntp_ts.lo = htonl(2);
+
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_ts) == 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_fuzz) < 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_fuzz, &ntp_ts) > 0);
+
+  ntp_fuzz.hi = htonl(0x90000001);
+
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_ts) == 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_ts, &ntp_fuzz) < 0);
+  TEST_CHECK(UTI_CompareNtp64(&ntp_fuzz, &ntp_ts) > 0);
+
+  ts.tv_sec = 1;
+  ts.tv_nsec = 2;
+  ts2.tv_sec = 1;
+  ts2.tv_nsec = 3;
+
+  TEST_CHECK(UTI_CompareTimespecs(&ts, &ts) == 0);
+  TEST_CHECK(UTI_CompareTimespecs(&ts, &ts2) < 0);
+  TEST_CHECK(UTI_CompareTimespecs(&ts2, &ts) > 0);
+
+  ts2.tv_sec = 2;
+
+  TEST_CHECK(UTI_CompareTimespecs(&ts, &ts) == 0);
+  TEST_CHECK(UTI_CompareTimespecs(&ts, &ts2) < 0);
+  TEST_CHECK(UTI_CompareTimespecs(&ts2, &ts) > 0);
+
+  for (i = -32; i <= 32; i++) {
+    for (j = c = 0; j < 1000; j++) {
+      UTI_GetNtp64Fuzz(&ntp_fuzz, i);
+      if (i <= 0)
+        TEST_CHECK(ntp_fuzz.hi == 0);
+      if (i < 0)
+        TEST_CHECK(ntohl(ntp_fuzz.lo) < 1U << (32 + i));
+      else if (i < 32)
+        TEST_CHECK(ntohl(ntp_fuzz.hi) < 1U << i);
+      if (ntohl(ntp_fuzz.lo) >= 1U << (31 + CLAMP(-31, i, 0)))
+        c++;
+    }
+
+    if (i == -32)
+      TEST_CHECK(c == 0);
+    else
+      TEST_CHECK(c > 400 && c < 600);
+  }
+
+  for (i = c = 0; i < 100000; i++) {
+    j = random() % (sizeof (buf) + 1);
+    UTI_GetRandomBytes(buf, j);
+    if (j && buf[j - 1] % 2)
+      c++;
+  }
+  TEST_CHECK(c > 46000 && c < 48000);
+}