diff --git a/test/unit/v1.test.js b/test/unit/v1.test.js
index 7f3a46f6..c0defc76 100644
--- a/test/unit/v1.test.js
+++ b/test/unit/v1.test.js
@@ -67,14 +67,16 @@ describe('v1', () => {
     );
   });
 
+  const fullOptions = {
+    msecs: 1321651533573,
+    nsecs: 5432,
+    clockseq: 0x385c,
+    node: [0x61, 0xcd, 0x3c, 0xbb, 0x32, 0x10],
+  };
+
   test('explicit options product expected id', () => {
     // Verify explicit options produce expected id
-    const id = v1({
-      msecs: 1321651533573,
-      nsecs: 5432,
-      clockseq: 0x385c,
-      node: [0x61, 0xcd, 0x3c, 0xbb, 0x32, 0x10],
-    });
+    const id = v1(fullOptions);
     assert(id === 'd9428888-122b-11e1-b85c-61cd3cbb3210', 'Explicit options produce expected id');
   });
 
@@ -88,4 +90,20 @@ describe('v1', () => {
     const dt = parseInt(after, 16) - parseInt(before, 16);
     assert(dt === 1, 'Ids spanning 1ms boundary are 100ns apart');
   });
+
+  const expectedBytes = [217, 66, 136, 136, 18, 43, 17, 225, 184, 92, 97, 205, 60, 187, 50, 16];
+
+  test('fills one UUID into a buffer as expected', () => {
+    const buffer = [];
+    const result = v1(fullOptions, buffer);
+    assert.deepEqual(buffer, expectedBytes);
+    assert.strictEqual(buffer, result);
+  });
+
+  test('fills two UUIDs into a buffer as expected', () => {
+    const buffer = [];
+    v1(fullOptions, buffer, 0);
+    v1(fullOptions, buffer, 16);
+    assert.deepEqual(buffer, expectedBytes.concat(expectedBytes));
+  });
 });
diff --git a/test/unit/v35.test.js b/test/unit/v35.test.js
index c7f5fc9e..fe1eda88 100644
--- a/test/unit/v35.test.js
+++ b/test/unit/v35.test.js
@@ -95,14 +95,10 @@ describe('v5', () => {
       0xf6,
     ];
 
-    v3('hello.example.com', v3.DNS, buf);
+    const result = v3('hello.example.com', v3.DNS, buf);
 
-    assert.ok(
-      buf.length === testBuf.length &&
-        buf.every(function (elem, idx) {
-          return elem === testBuf[idx];
-        }),
-    );
+    assert.deepEqual(buf, testBuf);
+    assert.strictEqual(result, buf);
 
     // test offsets as well
     buf = new Array(19);
@@ -113,13 +109,7 @@ describe('v5', () => {
 
     v3('hello.example.com', v3.DNS, buf, 3);
 
-    assert.ok(
-      buf.length === testBuf.length + 3 &&
-        buf.every(function (elem, idx) {
-          return idx >= 3 ? elem === testBuf[idx - 3] : elem === 'landmaster';
-        }),
-      'hello',
-    );
+    assert.deepEqual(buf, ['landmaster', 'landmaster', 'landmaster'].concat(testBuf));
   });
 
   test('v5', () => {
@@ -153,13 +143,9 @@ describe('v5', () => {
       0xec,
     ];
 
-    v5('hello.example.com', v5.DNS, buf);
-    assert.ok(
-      buf.length === testBuf.length &&
-        buf.every(function (elem, idx) {
-          return elem === testBuf[idx];
-        }),
-    );
+    const result = v5('hello.example.com', v5.DNS, buf);
+    assert.deepEqual(buf, testBuf);
+    assert.strictEqual(result, buf);
 
     // test offsets as well
     buf = new Array(19);
@@ -170,12 +156,7 @@ describe('v5', () => {
 
     v5('hello.example.com', v5.DNS, buf, 3);
 
-    assert.ok(
-      buf.length === testBuf.length + 3 &&
-        buf.every(function (elem, idx) {
-          return idx >= 3 ? elem === testBuf[idx - 3] : elem === 'landmaster';
-        }),
-    );
+    assert.deepEqual(buf, ['landmaster', 'landmaster', 'landmaster'].concat(testBuf));
   });
 
   test('v3/v5 constants', () => {