diff --git a/lib/istanbul/istanbul.js b/lib/istanbul/istanbul.js
index e50d562..850b3c2 100644
--- a/lib/istanbul/istanbul.js
+++ b/lib/istanbul/istanbul.js
@@ -144,7 +144,7 @@ const addUntestedFiles = async (istanbulData, options) => {
 
 };
 
-const mergeIstanbulDataList = (dataList) => {
+const mergeIstanbulDataList = (dataList, options) => {
     const istanbulCoverageList = dataList.map((it) => it.data);
     const coverageMap = istanbulLibCoverage.createCoverageMap();
     istanbulCoverageList.forEach((coverage) => {
@@ -155,7 +155,7 @@ const mergeIstanbulDataList = (dataList) => {
 };
 
 const mergeIstanbulCoverage = async (dataList, options) => {
-    const istanbulData = mergeIstanbulDataList(dataList);
+    const istanbulData = mergeIstanbulDataList(dataList, options);
     await addUntestedFiles(istanbulData, options);
     return istanbulData;
 };
diff --git a/lib/reports/raw.js b/lib/reports/raw.js
index 18f7f30..340ee2c 100644
--- a/lib/reports/raw.js
+++ b/lib/reports/raw.js
@@ -5,14 +5,14 @@ const { ZipFile } = require('../packages/monocart-coverage-vendor.js');
 const { mergeIstanbulDataList } = require('../istanbul/istanbul.js');
 const { mergeV8DataList } = require('../v8/v8.js');
 
-const getMergedData = (type, dataList) => {
+const getMergedData = (type, dataList, options) => {
     if (type === 'istanbul') {
-        return mergeIstanbulDataList(dataList);
+        return mergeIstanbulDataList(dataList, options);
     }
-    return mergeV8DataList(dataList);
+    return mergeV8DataList(dataList, options);
 };
 
-const mergeReport = async (rawDir, rawParent) => {
+const mergeReport = async (rawDir, options) => {
     const coverageFiles = fs.readdirSync(rawDir).filter((n) => n.endsWith('.json') && n.startsWith('coverage-'));
     // console.log(coverageFiles);
 
@@ -29,7 +29,7 @@ const mergeReport = async (rawDir, rawParent) => {
         Util.rmSync(jsonPath);
     }
 
-    const mergedData = await getMergedData(type, dataList);
+    const mergedData = await getMergedData(type, dataList, options);
 
     const dataId = Util.uid();
     const results = {
@@ -99,7 +99,7 @@ const rawReport = async (reportData, reportOptions, options) => {
 
     // merge
     if (rawOptions.merge) {
-        await mergeReport(rawDir, rawParent);
+        await mergeReport(rawDir, options);
     }
 
     // zip
diff --git a/lib/utils/gc.js b/lib/utils/gc.js
new file mode 100644
index 0000000..316337d
--- /dev/null
+++ b/lib/utils/gc.js
@@ -0,0 +1,9 @@
+const v8 = require('node:v8');
+const vm = require('node:vm');
+
+if (typeof global.gc !== 'function') {
+    v8.setFlagsFromString('--expose_gc');
+    global.gc = vm.runInNewContext('gc');
+}
+
+module.exports = global.gc;
diff --git a/lib/utils/util.js b/lib/utils/util.js
index 2fc35ec..9378e44 100644
--- a/lib/utils/util.js
+++ b/lib/utils/util.js
@@ -3,8 +3,6 @@ const { writeFile, readFile } = require('fs/promises');
 const path = require('path');
 const os = require('os');
 const crypto = require('crypto');
-const v8 = require('node:v8');
-const vm = require('node:vm');
 
 const EC = require('eight-colors');
 const CG = require('console-grid');
@@ -15,6 +13,7 @@ const request = require('./request.js');
 const version = require('../../package.json').version;
 const markdownGrid = require('./markdown.js');
 const { mergeV8Coverage } = require('./merge/merge.js');
+const gc = require('./gc.js');
 
 const {
     findUpSync, supportsColor, minimatch
@@ -40,6 +39,10 @@ const Util = {
     markdownGrid,
     mergeV8Coverage,
 
+    forceGC: () => {
+        gc();
+    },
+
     relativePath: function(p, root) {
         p = `${p}`;
         root = `${root || Util.root}`;
@@ -791,15 +794,6 @@ const Util = {
         return major1 - major2;
     },
 
-    forceGC: () => {
-        if (!Util.expose_gc) {
-            v8.setFlagsFromString('--expose_gc');
-            Util.expose_gc = true;
-        }
-        const gc = vm.runInNewContext('gc');
-        gc();
-    },
-
     // ==========================================================================================
 
     loggingLevels: {
diff --git a/lib/v8/v8.js b/lib/v8/v8.js
index c46fdaf..33a3a85 100644
--- a/lib/v8/v8.js
+++ b/lib/v8/v8.js
@@ -173,7 +173,7 @@ const mergeJsFunctions = async (itemList) => {
     return res.functions;
 };
 
-const mergeV8DataList = async (dataList) => {
+const mergeV8DataList = async (dataList, options) => {
     const allList = dataList.map((d) => d.data).flat();
 
     // separate coverage and empty items
@@ -233,14 +233,12 @@ const mergeV8DataList = async (dataList) => {
     // merged list + empty list
     const mergedList = Object.values(itemMap).concat(emptyList);
 
-    // Util.forceGC();
-
     return mergedList;
 };
 
 const mergeV8Coverage = async (dataList, sourceCache, options) => {
 
-    const mergedList = await mergeV8DataList(dataList);
+    const mergedList = await mergeV8DataList(dataList, options);
 
     // try to load coverage and source by id
     for (const entry of mergedList) {