diff --git a/test/parallel/test-trace-events-all.js b/test/parallel/test-trace-events-all.js
index d0cdd4a8749213..06e83fa6376208 100644
--- a/test/parallel/test-trace-events-all.js
+++ b/test/parallel/test-trace-events-all.js
@@ -6,7 +6,7 @@ const fs = require('fs');
 const path = require('path');
 
 const CODE =
-  'setTimeout(() => { for (var i = 0; i < 100000; i++) { "test" + i } }, 1)';
+  'setTimeout(() => { for (let i = 0; i < 100000; i++) { "test" + i } }, 1)';
 
 const tmpdir = require('../common/tmpdir');
 tmpdir.refresh();
diff --git a/test/parallel/test-trace-events-async-hooks-dynamic.js b/test/parallel/test-trace-events-async-hooks-dynamic.js
index 9cb0d41c5494c6..b660f7f8d49ee8 100644
--- a/test/parallel/test-trace-events-async-hooks-dynamic.js
+++ b/test/parallel/test-trace-events-async-hooks-dynamic.js
@@ -18,7 +18,7 @@ const path = require('path');
 const enable = `require("trace_events").createTracing(
 { categories: ["node.async_hooks"] }).enable();`;
 const code =
-  'setTimeout(() => { for (var i = 0; i < 100000; i++) { "test" + i } }, 1)';
+  'setTimeout(() => { for (let i = 0; i < 100000; i++) { "test" + i } }, 1)';
 
 const tmpdir = require('../common/tmpdir');
 const filename = path.join(tmpdir.path, 'node_trace.1.log');
diff --git a/test/parallel/test-trace-events-async-hooks-worker.js b/test/parallel/test-trace-events-async-hooks-worker.js
index 153ef301873151..185f310f89e13a 100644
--- a/test/parallel/test-trace-events-async-hooks-worker.js
+++ b/test/parallel/test-trace-events-async-hooks-worker.js
@@ -16,7 +16,7 @@ const fs = require('fs');
 const path = require('path');
 
 const code =
-  'setTimeout(() => { for (var i = 0; i < 100000; i++) { "test" + i } }, 1)';
+  'setTimeout(() => { for (let i = 0; i < 100000; i++) { "test" + i } }, 1)';
 const worker =
 `const { Worker } = require('worker_threads');
 const worker = new Worker('${code}',
diff --git a/test/parallel/test-trace-events-async-hooks.js b/test/parallel/test-trace-events-async-hooks.js
index 09017e47745c49..eecce9e5e43ab3 100644
--- a/test/parallel/test-trace-events-async-hooks.js
+++ b/test/parallel/test-trace-events-async-hooks.js
@@ -7,7 +7,7 @@ const path = require('path');
 const util = require('util');
 
 const CODE =
-  'setTimeout(() => { for (var i = 0; i < 100000; i++) { "test" + i } }, 1)';
+  'setTimeout(() => { for (let i = 0; i < 100000; i++) { "test" + i } }, 1)';
 
 const tmpdir = require('../common/tmpdir');
 tmpdir.refresh();
diff --git a/test/parallel/test-trace-events-file-pattern.js b/test/parallel/test-trace-events-file-pattern.js
index a60559b7f91b2b..d9cd8e66d23646 100644
--- a/test/parallel/test-trace-events-file-pattern.js
+++ b/test/parallel/test-trace-events-file-pattern.js
@@ -9,7 +9,7 @@ const path = require('path');
 tmpdir.refresh();
 
 const CODE =
-  'setTimeout(() => { for (var i = 0; i < 100000; i++) { "test" + i } }, 1)';
+  'setTimeout(() => { for (let i = 0; i < 100000; i++) { "test" + i } }, 1)';
 
 const proc = cp.spawn(process.execPath, [
   '--trace-events-enabled',
diff --git a/test/parallel/test-trace-events-metadata.js b/test/parallel/test-trace-events-metadata.js
index 863b2175f6c8a0..dbc8fc5d1ad5f9 100644
--- a/test/parallel/test-trace-events-metadata.js
+++ b/test/parallel/test-trace-events-metadata.js
@@ -6,7 +6,7 @@ const fs = require('fs');
 const path = require('path');
 
 const CODE =
-  'setTimeout(() => { for (var i = 0; i < 100000; i++) { "test" + i } }, 1);' +
+  'setTimeout(() => { for (let i = 0; i < 100000; i++) { "test" + i } }, 1);' +
   'process.title = "foo"';
 
 const tmpdir = require('../common/tmpdir');
diff --git a/test/parallel/test-trace-events-none.js b/test/parallel/test-trace-events-none.js
index dfe77e4b39369f..d6ec35677d3fe1 100644
--- a/test/parallel/test-trace-events-none.js
+++ b/test/parallel/test-trace-events-none.js
@@ -6,7 +6,7 @@ const fs = require('fs');
 const path = require('path');
 
 const CODE =
-  'setTimeout(() => { for (var i = 0; i < 100000; i++) { "test" + i } }, 1)';
+  'setTimeout(() => { for (let i = 0; i < 100000; i++) { "test" + i } }, 1)';
 
 const tmpdir = require('../common/tmpdir');
 tmpdir.refresh();
diff --git a/test/parallel/test-trace-events-v8.js b/test/parallel/test-trace-events-v8.js
index d79838892baa0d..0215a150e8a828 100644
--- a/test/parallel/test-trace-events-v8.js
+++ b/test/parallel/test-trace-events-v8.js
@@ -6,7 +6,7 @@ const fs = require('fs');
 const path = require('path');
 
 const CODE =
-  'setTimeout(() => { for (var i = 0; i < 100000; i++) { "test" + i } }, 1)';
+  'setTimeout(() => { for (let i = 0; i < 100000; i++) { "test" + i } }, 1)';
 
 const tmpdir = require('../common/tmpdir');
 tmpdir.refresh();