diff --git a/test/parallel/test-buffer-bigint64.js b/test/parallel/test-buffer-bigint64.js
index 60d376bdaf84af..a160d35b4a551a 100644
--- a/test/parallel/test-buffer-bigint64.js
+++ b/test/parallel/test-buffer-bigint64.js
@@ -7,49 +7,49 @@ const buf = Buffer.allocUnsafe(8);
 ['LE', 'BE'].forEach(function(endianness) {
   // Should allow simple BigInts to be written and read
   let val = 123456789n;
-  buf['writeBigInt64' + endianness](val, 0);
-  let rtn = buf['readBigInt64' + endianness](0);
+  buf[`writeBigInt64${endianness}`](val, 0);
+  let rtn = buf[`readBigInt64${endianness}`](0);
   assert.strictEqual(val, rtn);
 
   // Should allow INT64_MAX to be written and read
   val = 0x7fffffffffffffffn;
-  buf['writeBigInt64' + endianness](val, 0);
-  rtn = buf['readBigInt64' + endianness](0);
+  buf[`writeBigInt64${endianness}`](val, 0);
+  rtn = buf[`readBigInt64${endianness}`](0);
   assert.strictEqual(val, rtn);
 
   // Should read and write a negative signed 64-bit integer
   val = -123456789n;
-  buf['writeBigInt64' + endianness](val, 0);
-  assert.strictEqual(val, buf['readBigInt64' + endianness](0));
+  buf[`writeBigInt64${endianness}`](val, 0);
+  assert.strictEqual(val, buf[`readBigInt64${endianness}`](0));
 
   // Should read and write an unsigned 64-bit integer
   val = 123456789n;
-  buf['writeBigUInt64' + endianness](val, 0);
-  assert.strictEqual(val, buf['readBigUInt64' + endianness](0));
+  buf[`writeBigUInt64${endianness}`](val, 0);
+  assert.strictEqual(val, buf[`readBigUInt64${endianness}`](0));
 
   // Should throw a RangeError upon INT64_MAX+1 being written
   assert.throws(function() {
     const val = 0x8000000000000000n;
-    buf['writeBigInt64' + endianness](val, 0);
+    buf[`writeBigInt64${endianness}`](val, 0);
   }, RangeError);
 
   // Should throw a RangeError upon UINT64_MAX+1 being written
   assert.throws(function() {
     const val = 0x10000000000000000n;
-    buf['writeBigUInt64' + endianness](val, 0);
+    buf[`writeBigUInt64${endianness}`](val, 0);
   }, {
     code: 'ERR_OUT_OF_RANGE',
     message: 'The value of "value" is out of range. It must be ' +
-             '>= 0n and < 2n ** 64n. Received 18_446_744_073_709_551_616n'
+      '>= 0n and < 2n ** 64n. Received 18_446_744_073_709_551_616n'
   });
 
   // Should throw a TypeError upon invalid input
   assert.throws(function() {
-    buf['writeBigInt64' + endianness]('bad', 0);
+    buf[`writeBigInt64${endianness}`]('bad', 0);
   }, TypeError);
 
   // Should throw a TypeError upon invalid input
   assert.throws(function() {
-    buf['writeBigUInt64' + endianness]('bad', 0);
+    buf[`writeBigUInt64${endianness}`]('bad', 0);
   }, TypeError);
 });
diff --git a/test/parallel/test-http-readable-data-event.js b/test/parallel/test-http-readable-data-event.js
index 21b1fa65c661c8..643176ec7b066a 100644
--- a/test/parallel/test-http-readable-data-event.js
+++ b/test/parallel/test-http-readable-data-event.js
@@ -10,14 +10,14 @@ let next = null;
 
 const server = http.createServer((req, res) => {
   res.writeHead(200, {
-    'Content-Length': '' + (helloWorld.length + helloAgainLater.length)
+    'Content-Length': `${(helloWorld.length + helloAgainLater.length)}`
   });
 
   // We need to make sure the data is flushed
   // before writing again
   next = () => {
     res.end(helloAgainLater);
-    next = () => {};
+    next = () => { };
   };
 
   res.write(helloWorld);
diff --git a/test/parallel/test-http2-origin.js b/test/parallel/test-http2-origin.js
index 6f90a043d8a7cc..519e8cb1a3dedd 100644
--- a/test/parallel/test-http2-origin.js
+++ b/test/parallel/test-http2-origin.js
@@ -70,7 +70,7 @@ const ca = readKey('fake-startcom-root-cert.pem', 'binary');
         }
       );
     });
-    const longInput = 'http://foo.bar' + 'a'.repeat(16383);
+    const longInput = `http://foo.bar${'a'.repeat(16383)}`;
     throws(
       () => session.origin(longInput),
       {
@@ -107,7 +107,7 @@ const ca = readKey('fake-startcom-root-cert.pem', 'binary');
 
 // Test automatically sending origin on connection start
 {
-  const origins = [ 'https://foo.org/a/b/c', 'https://bar.org' ];
+  const origins = ['https://foo.org/a/b/c', 'https://bar.org'];
   const server = createSecureServer({ key, cert, origins });
   server.on('stream', mustCall((stream) => {
     stream.respond();
diff --git a/test/parallel/test-http2-server-session-destroy.js b/test/parallel/test-http2-server-session-destroy.js
index 9b7f126510757c..afa3dd3398dba8 100644
--- a/test/parallel/test-http2-server-session-destroy.js
+++ b/test/parallel/test-http2-server-session-destroy.js
@@ -16,5 +16,5 @@ server.listen(0, common.localhostIPv4, common.mustCall(() => {
 
   const port = server.address().port;
   const host = common.localhostIPv4;
-  h2.connect('http://' + host + ':' + port, afterConnect);
+  h2.connect(`http://${host}:${port}`, afterConnect);
 }));
diff --git a/test/parallel/test-promises-warning-on-unhandled-rejection.js b/test/parallel/test-promises-warning-on-unhandled-rejection.js
index ba420157e72bbd..596bf27ad1917d 100644
--- a/test/parallel/test-promises-warning-on-unhandled-rejection.js
+++ b/test/parallel/test-promises-warning-on-unhandled-rejection.js
@@ -23,7 +23,7 @@ process.on('warning', common.mustCall((warning) => {
       assert(
         /Unhandled promise rejection/.test(warning.message),
         'Expected warning message to contain "Unhandled promise rejection" ' +
-        'but did not. Had "' + warning.message + '" instead.'
+        `but did not. Had "${warning.message}" instead.`
       );
       break;
     case 2:
@@ -40,7 +40,7 @@ process.on('warning', common.mustCall((warning) => {
       assert(
         /Unhandled promise rejection/.test(warning.message),
         'Expected warning message to contain "Unhandled promise rejection" ' +
-        'but did not. Had "' + warning.message + '" instead.'
+        `but did not. Had "${warning.message}" instead.`
       );
       break;
     case 5:
diff --git a/test/parallel/test-tls-psk-server.js b/test/parallel/test-tls-psk-server.js
index 69b850c70226a6..434d31380fe2ad 100644
--- a/test/parallel/test-tls-psk-server.js
+++ b/test/parallel/test-tls-psk-server.js
@@ -43,7 +43,7 @@ let gotWorld = false;
 server.listen(0, () => {
   const client = spawn(common.opensslCli, [
     's_client',
-    '-connect', '127.0.0.1:' + server.address().port,
+    '-connect', `127.0.0.1:${server.address().port}`,
     '-cipher', CIPHERS,
     '-psk', KEY,
     '-psk_identity', IDENTITY
diff --git a/test/parallel/test-worker-relative-path.js b/test/parallel/test-worker-relative-path.js
index 3b7bb95b0d78f4..73dc5b3637912f 100644
--- a/test/parallel/test-worker-relative-path.js
+++ b/test/parallel/test-worker-relative-path.js
@@ -5,7 +5,7 @@ const assert = require('assert');
 const { Worker, isMainThread, parentPort } = require('worker_threads');
 
 if (isMainThread) {
-  const w = new Worker('./' + path.relative('.', __filename));
+  const w = new Worker(`./${path.relative('.', __filename)}`);
   w.on('message', common.mustCall((message) => {
     assert.strictEqual(message, 'Hello, world!');
   }));