diff --git a/Makefile b/Makefile
index 6c457dfc3d894d..85950cb95ca7c5 100644
--- a/Makefile
+++ b/Makefile
@@ -593,7 +593,6 @@ test-wpt-report:
 	$(RM) -r out/wpt
 	mkdir -p out/wpt
 	WPT_REPORT=1 $(PYTHON) tools/test.py --shell $(NODE) $(PARALLEL_ARGS) wpt
-	$(NODE) "$$PWD/tools/merge-wpt-reports.mjs"
 
 .PHONY: test-internet
 test-internet: all
diff --git a/test/common/wpt.js b/test/common/wpt.js
index 342324182138ea..57c409f5cc8a0f 100644
--- a/test/common/wpt.js
+++ b/test/common/wpt.js
@@ -10,8 +10,6 @@ const os = require('os');
 const { inspect } = require('util');
 const { Worker } = require('worker_threads');
 
-const workerPath = path.join(__dirname, 'wpt/worker.js');
-
 function getBrowserProperties() {
   const { node: version } = process.versions; // e.g. 18.13.0, 20.0.0-nightly202302078e6e215481
   const release = /^\d+\.\d+\.\d+$/.test(version);
@@ -59,8 +57,7 @@ function codeUnitStr(char) {
 }
 
 class WPTReport {
-  constructor(path) {
-    this.filename = `report-${path.replaceAll('/', '-')}.json`;
+  constructor() {
     this.results = [];
     this.time_start = Date.now();
   }
@@ -99,18 +96,26 @@ class WPTReport {
       return result;
     });
 
-    /**
-     * Return required and some optional properties
-     * https://github.com/web-platform-tests/wpt.fyi/blob/60da175/api/README.md?plain=1#L331-L335
-     */
-    this.run_info = {
-      product: 'node.js',
-      ...getBrowserProperties(),
-      revision: process.env.WPT_REVISION || 'unknown',
-      os: getOs(),
-    };
+    if (fs.existsSync('out/wpt/wptreport.json')) {
+      const prev = JSON.parse(fs.readFileSync('out/wpt/wptreport.json'));
+      this.results = [...prev.results, ...this.results];
+      this.time_start = prev.time_start;
+      this.time_end = Math.max(this.time_end, prev.time_end);
+      this.run_info = prev.run_info;
+    } else {
+      /**
+       * Return required and some optional properties
+       * https://github.com/web-platform-tests/wpt.fyi/blob/60da175/api/README.md?plain=1#L331-L335
+       */
+      this.run_info = {
+        product: 'node.js',
+        ...getBrowserProperties(),
+        revision: process.env.WPT_REVISION || 'unknown',
+        os: getOs(),
+      };
+    }
 
-    fs.writeFileSync(`out/wpt/${this.filename}`, JSON.stringify(this));
+    fs.writeFileSync('out/wpt/wptreport.json', JSON.stringify(this));
   }
 }
 
@@ -397,29 +402,6 @@ const kIncomplete = 'incomplete';
 const kUncaught = 'uncaught';
 const NODE_UNCAUGHT = 100;
 
-const limit = (concurrency) => {
-  let running = 0;
-  const queue = [];
-
-  const execute = async (fn) => {
-    if (running < concurrency) {
-      running++;
-      try {
-        await fn();
-      } finally {
-        running--;
-        if (queue.length > 0) {
-          execute(queue.shift());
-        }
-      }
-    } else {
-      queue.push(fn);
-    }
-  };
-
-  return execute;
-};
-
 class WPTRunner {
   constructor(path) {
     this.path = path;
@@ -443,7 +425,7 @@ class WPTRunner {
     this.scriptsModifier = null;
 
     if (process.env.WPT_REPORT != null) {
-      this.report = new WPTReport(path);
+      this.report = new WPTReport();
     }
   }
 
@@ -561,8 +543,6 @@ class WPTRunner {
 
     this.inProgress = new Set(queue.map((spec) => spec.filename));
 
-    const run = limit(os.availableParallelism());
-
     for (const spec of queue) {
       const testFileName = spec.filename;
       const content = spec.getContent();
@@ -596,7 +576,15 @@ class WPTRunner {
       this.scriptsModifier?.(obj);
       scriptsToRun.push(obj);
 
-      const runWorker = async (variant) => {
+      /**
+       * Example test with no META variant
+       * https://github.com/nodejs/node/blob/03854f6/test/fixtures/wpt/WebCryptoAPI/sign_verify/hmac.https.any.js#L1-L4
+       *
+       * Example test with multiple META variants
+       * https://github.com/nodejs/node/blob/03854f6/test/fixtures/wpt/WebCryptoAPI/generateKey/successes_RSASSA-PKCS1-v1_5.https.any.js#L1-L9
+       */
+      for (const variant of meta.variant || ['']) {
+        const workerPath = path.join(__dirname, 'wpt/worker.js');
         const worker = new Worker(workerPath, {
           execArgv: this.flags,
           workerData: {
@@ -647,17 +635,6 @@ class WPTRunner {
         });
 
         await events.once(worker, 'exit').catch(() => {});
-      };
-
-      /**
-       * Example test with no META variant
-       * https://github.com/nodejs/node/blob/03854f6/test/fixtures/wpt/WebCryptoAPI/sign_verify/hmac.https.any.js#L1-L4
-       *
-       * Example test with multiple META variants
-       * https://github.com/nodejs/node/blob/03854f6/test/fixtures/wpt/WebCryptoAPI/generateKey/successes_RSASSA-PKCS1-v1_5.https.any.js#L1-L9
-       */
-      for (const variant of meta.variant || ['']) {
-        run(() => runWorker(variant));
       }
     }
 
diff --git a/test/wpt/testcfg.py b/test/wpt/testcfg.py
index db235699ddfe57..3c356cf474d83c 100644
--- a/test/wpt/testcfg.py
+++ b/test/wpt/testcfg.py
@@ -3,4 +3,4 @@
 import testpy
 
 def GetConfiguration(context, root):
-  return testpy.ParallelTestConfiguration(context, root, 'wpt')
+  return testpy.SimpleTestConfiguration(context, root, 'wpt')
diff --git a/tools/merge-wpt-reports.mjs b/tools/merge-wpt-reports.mjs
deleted file mode 100644
index 9199714f4b1032..00000000000000
--- a/tools/merge-wpt-reports.mjs
+++ /dev/null
@@ -1,32 +0,0 @@
-import * as fs from 'node:fs';
-import * as path from 'node:path';
-import * as url from 'node:url';
-
-const __dirname = path.dirname(url.fileURLToPath(import.meta.url));
-
-const outDir = path.resolve(__dirname, '../out/wpt');
-const files = fs.readdirSync(outDir);
-const reports = files.filter((file) => file.endsWith('.json'));
-
-const startTimes = [];
-const endTimes = [];
-const results = [];
-let runInfo;
-
-for (const file of reports) {
-  const report = JSON.parse(fs.readFileSync(path.resolve(outDir, file)));
-  fs.unlinkSync(path.resolve(outDir, file));
-  results.push(...report.results);
-  startTimes.push(report.time_start);
-  endTimes.push(report.time_end);
-  runInfo ||= report.run_info;
-}
-
-const mergedReport = {
-  time_start: Math.min(...startTimes),
-  time_end: Math.max(...endTimes),
-  run_info: runInfo,
-  results,
-};
-
-fs.writeFileSync(path.resolve(outDir, 'wptreport.json'), JSON.stringify(mergedReport));