diff --git a/.gitignore b/.gitignore
index ea00b8f0..657bcd13 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ out
 coverage
 test/**/dist
 test/**/actual.js
+test/unit/cjs-querystring/who?what?idk!.js
diff --git a/src/node-file-trace.ts b/src/node-file-trace.ts
index 9eb8e825..ab8742ee 100644
--- a/src/node-file-trace.ts
+++ b/src/node-file-trace.ts
@@ -7,6 +7,31 @@ import { sharedLibEmit } from './utils/sharedlib-emit';
 import { join } from 'path';
 import { CachedFileSystem } from './fs';
 
+type ParseSpecifierResult = {
+  remainingSpecifier: string;
+  queryString: string | null
+}
+
+// Splits an ESM specifier into path and querystring (including the leading `?`). (If the specifier is CJS,
+// it is passed through untouched.)
+export function splitQueryStringFromSpecifier(specifier: string, cjsResolve: boolean = true): ParseSpecifierResult {
+  let remainingSpecifier = specifier;
+  let queryString = null;
+
+  if (!cjsResolve) {
+    const specifierUrl = new URL(specifier, "placeholder-protocol://");
+    queryString = specifierUrl.search;
+
+    if (specifierUrl.search) {
+      remainingSpecifier = specifier.replace(specifierUrl.search, '');
+    } else {
+      remainingSpecifier = specifier;
+    }
+  }
+
+  return {queryString, remainingSpecifier};
+}
+
 function inPath (path: string, parent: string) {
   const pathWithSep = join(parent, sep);
   return path.startsWith(pathWithSep) && path !== pathWithSep;
@@ -163,6 +188,8 @@ export class Job {
   }
 
   private maybeEmitDep = async (dep: string, path: string, cjsResolve: boolean) => {
+    // Only affects ESM dependencies
+    const { remainingSpecifier: strippedDep, queryString = '' } = splitQueryStringFromSpecifier(dep, cjsResolve)
     let resolved: string | string[] = '';
     let error: Error | undefined;
     try {
@@ -170,12 +197,12 @@ export class Job {
     } catch (e1: any) {
       error = e1;
       try {
-        if (this.ts && dep.endsWith('.js') && e1 instanceof NotFoundError) {
+        if (this.ts && strippedDep.endsWith('.js') && e1 instanceof NotFoundError) {
           // TS with ESM relative import paths need full extensions
           // (we have to write import "./foo.js" instead of import "./foo")
           // See https://www.typescriptlang.org/docs/handbook/esm-node.html
-          const depTS = dep.slice(0, -3) + '.ts';
-          resolved = await this.resolve(depTS, path, this, cjsResolve);
+          const strippedDepTS = strippedDep.slice(0, -3) + '.ts';
+          resolved = await this.resolve(strippedDepTS + queryString, path, this, cjsResolve);
           error = undefined;
         }
       } catch (e2: any) {
@@ -188,16 +215,19 @@ export class Job {
       return;
     }
 
-    if (Array.isArray(resolved)) {
-      for (const item of resolved) {
-        // ignore builtins
-        if (item.startsWith('node:')) return;
-        await this.emitDependency(item, path);
+    // For simplicity, force `resolved` to be an array
+    resolved = Array.isArray(resolved) ? resolved : [resolved];
+    for (let item of resolved) {
+      // ignore builtins for the purposes of both tracing and querystring handling (neither Node 
+      // nor Webpack can handle querystrings on `node:xxx` imports).
+      if (item.startsWith('node:')) return;
+
+      // If querystring was stripped during resolution, restore it
+      if (queryString && !item.endsWith(queryString)) {
+        item += queryString;
       }
-    } else {
-      // ignore builtins
-      if (resolved.startsWith('node:')) return;
-      await this.emitDependency(resolved, path);
+      
+      await this.analyzeAndEmitDependency(item, path, cjsResolve);
     }
   }
 
@@ -274,13 +304,23 @@ export class Job {
   }
 
   async emitDependency (path: string, parent?: string) {
-    if (this.processed.has(path)) {
+    return this.analyzeAndEmitDependency(path, parent)
+  }
+
+  private async analyzeAndEmitDependency(rawPath: string, parent?: string, cjsResolve?: boolean) {
+
+    // Strip the querystring, if any. (Only affects ESM dependencies.)
+    const { remainingSpecifier: path } = splitQueryStringFromSpecifier(rawPath, cjsResolve)
+
+    // Since different querystrings may lead to different results, include the full path
+    // when noting whether or not we've already seen this path
+    if (this.processed.has(rawPath)) {
       if (parent) {
         await this.emitFile(path, 'dependency', parent)
       }
       return
     };
-    this.processed.add(path);
+    this.processed.add(rawPath);
 
     const emitted = await this.emitFile(path, 'dependency', parent);
     if (!emitted) return;
@@ -299,18 +339,34 @@ export class Job {
 
     let analyzeResult: AnalyzeResult;
 
-    const cachedAnalysis = this.analysisCache.get(path);
+    // Since different querystrings may lead to analyses, include the full path when caching
+    const cachedAnalysis = this.analysisCache.get(rawPath);
     if (cachedAnalysis) {
       analyzeResult = cachedAnalysis;
     }
     else {
-      const source = await this.readFile(path);
-      if (source === null) throw new Error('File ' + path + ' does not exist.');
+      // By default, `this.readFile` is the regular `fs.readFile`, but a different implementation
+      // can be specified via a user option in the main `nodeFileTrace` entrypoint. Depending on
+      // that implementation, having a querystring on the end of the path may either a) be necessary
+      // in order to specify the right module from which to read, or b) lead to an `ENOENT: no such
+      // file or directory` error because it thinks the querystring is part of the filename. We
+      // therefore try it with the querystring first, but have the non-querystringed version as a
+      // fallback. (If there's no `?` in the given path, `rawPath` will equal `path`, so order is a
+      // moot point.)
+      const source = await this.readFile(rawPath) || await this.readFile(path) ;
+
+      if (source === null) {
+        const errorMessage = path === rawPath
+          ? 'File ' + path + ' does not exist.'
+          : 'Neither ' + path + ' nor ' + rawPath + ' exists.'
+        throw new Error(errorMessage);
+      }
+      
       // analyze should not have any side-effects e.g. calling `job.emitFile`
       // directly as this will not be included in the cachedAnalysis and won't
       // be emit for successive runs that leverage the cache
       analyzeResult = await analyze(path, source.toString(), this);
-      this.analysisCache.set(path, analyzeResult);
+      this.analysisCache.set(rawPath, analyzeResult);
     }
 
     const { deps, imports, assets, isESM } = analyzeResult;
@@ -324,12 +380,12 @@ export class Job {
         const ext = extname(asset);
         if (ext === '.js' || ext === '.mjs' || ext === '.node' || ext === '' ||
             this.ts && (ext === '.ts' || ext === '.tsx') && asset.startsWith(this.base) && asset.slice(this.base.length).indexOf(sep + 'node_modules' + sep) === -1)
-          await this.emitDependency(asset, path);
+          await this.analyzeAndEmitDependency(asset, path, !isESM);
         else
           await this.emitFile(asset, 'asset', path);
       }),
-      ...[...deps].map(async dep => this.maybeEmitDep(dep, path, !isESM)),
-      ...[...imports].map(async dep => this.maybeEmitDep(dep, path, false)),
+      ...[...deps].map(async dep => this.maybeEmitDep(dep, rawPath, !isESM)),
+      ...[...imports].map(async dep => this.maybeEmitDep(dep, rawPath, false)),
     ]);
   }
 }
\ No newline at end of file
diff --git a/src/resolve-dependency.ts b/src/resolve-dependency.ts
index b50684f4..01fcff8e 100644
--- a/src/resolve-dependency.ts
+++ b/src/resolve-dependency.ts
@@ -1,11 +1,16 @@
 import { isAbsolute, resolve, sep } from 'path';
-import { Job } from './node-file-trace';
+import { Job, splitQueryStringFromSpecifier } from './node-file-trace';
 
 // node resolver
 // custom implementation to emit only needed package.json files for resolver
 // (package.json files are emitted as they are hit)
 export default async function resolveDependency (specifier: string, parent: string, job: Job, cjsResolve = true): Promise<string | string[]> {
   let resolved: string | string[];
+
+  // ESM imports are allowed to have querystrings, but the native Node behavior is to ignore them when doing
+  // file resolution, so emulate that here by stripping any querystring off before continuing
+  specifier = splitQueryStringFromSpecifier(specifier, cjsResolve).remainingSpecifier
+
   if (isAbsolute(specifier) || specifier === '.' || specifier === '..' || specifier.startsWith('./') || specifier.startsWith('../')) {
     const trailingSlash = specifier.endsWith('/');
     resolved = await resolvePath(resolve(parent, '..', specifier) + (trailingSlash ? '/' : ''), parent, job);
diff --git a/test/unit.test.js b/test/unit.test.js
index d797f609..7862aef2 100644
--- a/test/unit.test.js
+++ b/test/unit.test.js
@@ -1,5 +1,5 @@
 const fs = require('fs');
-const { join, relative } = require('path');
+const { join, relative, sep } = require('path');
 const { nodeFileTrace } = require('../out/node-file-trace');
 const gracefulFS = require('graceful-fs');
 const analyze = require('../out/analyze.js').default;
@@ -10,11 +10,11 @@ const readFile = gracefulFS.promises.readFile
 
 global._unit = true;
 
-const skipOnWindows = ['yarn-workspaces', 'yarn-workspaces-base-root', 'yarn-workspace-esm', 'asset-symlink', 'require-symlink'];
+const skipOnWindows = ['yarn-workspaces', 'yarn-workspaces-base-root', 'yarn-workspace-esm', 'asset-symlink', 'require-symlink', 'cjs-querystring'];
 const unitTestDirs = fs.readdirSync(join(__dirname, 'unit'));
 const unitTests = [
-  ...unitTestDirs.map(testName => ({testName, isRoot: false})),
   ...unitTestDirs.map(testName => ({testName, isRoot: true})),
+  ...unitTestDirs.map(testName => ({testName, isRoot: false})),
 ];
 
 jest.mock('../out/analyze.js', () => {
@@ -51,12 +51,28 @@ afterEach(resetFileIOMocks)
 
 for (const { testName, isRoot } of unitTests) {
   const testSuffix = `${testName} from ${isRoot ? 'root' : 'cwd'}`;
-  if (process.platform === 'win32' && (isRoot || skipOnWindows.includes(testName))) {
-    console.log(`Skipping unit test on Windows: ${testSuffix}`);
-    continue;
-  };
   const unitPath = join(__dirname, 'unit', testName);
 
+  if (process.platform === 'win32') { 
+    if (isRoot || skipOnWindows.includes(testName)) {
+      console.log(`Skipping unit test on Windows: ${testSuffix}`);
+      continue;
+    }
+  } else {
+    if (testName === 'cjs-querystring') {
+      // Create (a git-ignored copy of) the file we need, since committing it
+      // breaks CI on Windows. See https://github.com/vercel/nft/pull/322.
+      const currentFilepath = join(unitPath, 'noPunctuation', 'whowhatidk.js');
+      const newFilepath = currentFilepath.replace(
+        'noPunctuation' + sep + 'whowhatidk.js',
+        'who?what?idk!.js'
+      );
+      if (!fs.existsSync(newFilepath)) {
+        fs.copyFileSync(currentFilepath, newFilepath);
+      }
+    }
+  }
+  
   it(`should correctly trace ${testSuffix}`, async () => {
 
     // We mock readFile because when node-file-trace is integrated into @now/node
@@ -79,6 +95,25 @@ for (const { testName, isRoot } of unitTests) {
           return null
         }
       }
+
+      // mock an in-memory module store (such as webpack's) where the same filename with
+      // two different querystrings can correspond to two different modules, one importing
+      // the other
+      if (testName === 'querystring-self-import') {
+        if (id.endsWith('input.js') || id.endsWith('base.js') || id.endsWith('dep.js')) {
+          return fs.readFileSync(id).toString()
+        }
+
+        if (id.endsWith('base.js?__withQuery')) {
+          return `
+            import * as origBase from './base';
+            export const dogs = origBase.dogs.concat('Cory', 'Bodhi');
+            export const cats = origBase.cats.concat('Teaberry', 'Sassafras', 'Persephone');
+            export const rats = origBase.rats;
+          `;
+        }
+      }
+
       return this.constructor.prototype.readFile.apply(this, arguments);
     });
 
@@ -106,7 +141,7 @@ for (const { testName, isRoot } of unitTests) {
         inputFileNames.push('input-2.js', 'input-3.js', 'input-4.js');
       }
 
-      const { fileList, reasons } = await nodeFileTrace(
+      const { fileList, reasons, warnings } = await nodeFileTrace(
         inputFileNames.map(file => join(unitPath, file)),
         {
           base: isRoot ? '/' : `${__dirname}/../`,
@@ -231,7 +266,7 @@ for (const { testName, isRoot } of unitTests) {
         expect(sortedFileList).toEqual(expected);
       }
       catch (e) {
-        console.warn(reasons);
+        console.warn({reasons, warnings});
         fs.writeFileSync(join(unitPath, 'actual.js'), JSON.stringify(sortedFileList, null, 2));
         throw e;
       }
diff --git a/test/unit/cjs-querystring/input.js b/test/unit/cjs-querystring/input.js
new file mode 100644
index 00000000..5a1baf7e
--- /dev/null
+++ b/test/unit/cjs-querystring/input.js
@@ -0,0 +1,7 @@
+// Test that CJS files treat question marks in filenames as any other character,
+// matching Node behavior
+
+// https://www.youtube.com/watch?v=2ve20PVNZ18
+
+const baseball = require('./who?what?idk!');
+console.log(baseball.players);
diff --git a/test/unit/cjs-querystring/noPunctuation/whowhatidk.js b/test/unit/cjs-querystring/noPunctuation/whowhatidk.js
new file mode 100644
index 00000000..4c4c4b72
--- /dev/null
+++ b/test/unit/cjs-querystring/noPunctuation/whowhatidk.js
@@ -0,0 +1,12 @@
+module.exports = {
+  players: {
+    first: 'Who',
+    second: 'What',
+    third: "I Don't Know",
+    left: 'Why',
+    center: 'Because',
+    pitcher: 'Tomorrow',
+    catcher: 'Today',
+    shortstop: "I Don't Give a Damn!",
+  },
+};
diff --git a/test/unit/cjs-querystring/output.js b/test/unit/cjs-querystring/output.js
new file mode 100644
index 00000000..296a204b
--- /dev/null
+++ b/test/unit/cjs-querystring/output.js
@@ -0,0 +1,5 @@
+[
+  "package.json",
+  "test/unit/cjs-querystring/input.js",
+  "test/unit/cjs-querystring/who?what?idk!.js"
+]
diff --git a/test/unit/esm-querystring-mjs/animalFacts/aardvark.mjs b/test/unit/esm-querystring-mjs/animalFacts/aardvark.mjs
new file mode 100644
index 00000000..a2efff8a
--- /dev/null
+++ b/test/unit/esm-querystring-mjs/animalFacts/aardvark.mjs
@@ -0,0 +1,4 @@
+import { numSpecies } from "./bear.mjs?beaver?bison";
+console.log(`There are ${numSpecies} species of bears.`);
+
+export const food = "termites";
diff --git a/test/unit/esm-querystring-mjs/animalFacts/bear.mjs b/test/unit/esm-querystring-mjs/animalFacts/bear.mjs
new file mode 100644
index 00000000..a8ee2dd0
--- /dev/null
+++ b/test/unit/esm-querystring-mjs/animalFacts/bear.mjs
@@ -0,0 +1,4 @@
+import * as cheetah from "./cheetah.mjs?cow=chipmunk";
+console.log(`Cheetahs can run ${cheetah.topSpeed} mph.`);
+
+export const numSpecies = 8;
diff --git a/test/unit/esm-querystring-mjs/animalFacts/cheetah.mjs b/test/unit/esm-querystring-mjs/animalFacts/cheetah.mjs
new file mode 100644
index 00000000..836b4ddf
--- /dev/null
+++ b/test/unit/esm-querystring-mjs/animalFacts/cheetah.mjs
@@ -0,0 +1 @@
+export const topSpeed = 65;
diff --git a/test/unit/esm-querystring-mjs/input.js b/test/unit/esm-querystring-mjs/input.js
new file mode 100644
index 00000000..a07ace77
--- /dev/null
+++ b/test/unit/esm-querystring-mjs/input.js
@@ -0,0 +1,6 @@
+// Test that querystrings of various forms get stripped from esm imports when those
+// imports contain the `.mjs` file extension
+
+import * as aardvark from "./animalFacts/aardvark.mjs?anteater";
+
+console.log(`Aardvarks eat ${aardvark.food}.`);
diff --git a/test/unit/esm-querystring-mjs/output.js b/test/unit/esm-querystring-mjs/output.js
new file mode 100644
index 00000000..95137ed7
--- /dev/null
+++ b/test/unit/esm-querystring-mjs/output.js
@@ -0,0 +1,7 @@
+[
+  "test/unit/esm-querystring-mjs/animalFacts/aardvark.mjs",
+  "test/unit/esm-querystring-mjs/animalFacts/bear.mjs",
+  "test/unit/esm-querystring-mjs/animalFacts/cheetah.mjs",
+  "test/unit/esm-querystring-mjs/input.js",
+  "test/unit/esm-querystring-mjs/package.json"
+]
\ No newline at end of file
diff --git a/test/unit/esm-querystring-mjs/package.json b/test/unit/esm-querystring-mjs/package.json
new file mode 100644
index 00000000..e986b24b
--- /dev/null
+++ b/test/unit/esm-querystring-mjs/package.json
@@ -0,0 +1,4 @@
+{
+  "private": true,
+  "type": "module"
+}
diff --git a/test/unit/esm-querystring/animalFacts/aardvark.js b/test/unit/esm-querystring/animalFacts/aardvark.js
new file mode 100644
index 00000000..4c497265
--- /dev/null
+++ b/test/unit/esm-querystring/animalFacts/aardvark.js
@@ -0,0 +1,4 @@
+import { numSpecies } from './bear?beaver?bison';
+console.log(`There are ${numSpecies} species of bears.`);
+
+export const food = 'termites';
diff --git a/test/unit/esm-querystring/animalFacts/bear.js b/test/unit/esm-querystring/animalFacts/bear.js
new file mode 100644
index 00000000..4578358b
--- /dev/null
+++ b/test/unit/esm-querystring/animalFacts/bear.js
@@ -0,0 +1,4 @@
+import * as cheetah from './cheetah?cow=chipmunk';
+console.log(`Cheetahs can run ${cheetah.topSpeed} mph.`);
+
+export const numSpecies = 8;
diff --git a/test/unit/esm-querystring/animalFacts/cheetah.js b/test/unit/esm-querystring/animalFacts/cheetah.js
new file mode 100644
index 00000000..836b4ddf
--- /dev/null
+++ b/test/unit/esm-querystring/animalFacts/cheetah.js
@@ -0,0 +1 @@
+export const topSpeed = 65;
diff --git a/test/unit/esm-querystring/input.js b/test/unit/esm-querystring/input.js
new file mode 100644
index 00000000..b0d51697
--- /dev/null
+++ b/test/unit/esm-querystring/input.js
@@ -0,0 +1,5 @@
+// Test that querystrings of various forms get stripped from esm imports
+
+import * as aardvark from './animalFacts/aardvark?anteater';
+
+console.log(`Aardvarks eat ${aardvark.food}.`);
diff --git a/test/unit/esm-querystring/output.js b/test/unit/esm-querystring/output.js
new file mode 100644
index 00000000..d03f7cb8
--- /dev/null
+++ b/test/unit/esm-querystring/output.js
@@ -0,0 +1,7 @@
+[
+  "test/unit/esm-querystring/animalFacts/aardvark.js",
+  "test/unit/esm-querystring/animalFacts/bear.js",
+  "test/unit/esm-querystring/animalFacts/cheetah.js",
+  "test/unit/esm-querystring/input.js",
+  "test/unit/esm-querystring/package.json"
+]
\ No newline at end of file
diff --git a/test/unit/esm-querystring/package.json b/test/unit/esm-querystring/package.json
new file mode 100644
index 00000000..e986b24b
--- /dev/null
+++ b/test/unit/esm-querystring/package.json
@@ -0,0 +1,4 @@
+{
+  "private": true,
+  "type": "module"
+}
diff --git a/test/unit/querystring-self-import/base.js b/test/unit/querystring-self-import/base.js
new file mode 100644
index 00000000..8f48a38a
--- /dev/null
+++ b/test/unit/querystring-self-import/base.js
@@ -0,0 +1,5 @@
+import * as dep from './dep';
+
+export const dogs = ['Charlie', 'Maisey'];
+export const cats = ['Piper'];
+export const rats = dep.rats;
diff --git a/test/unit/querystring-self-import/dep.js b/test/unit/querystring-self-import/dep.js
new file mode 100644
index 00000000..aaff193a
--- /dev/null
+++ b/test/unit/querystring-self-import/dep.js
@@ -0,0 +1 @@
+export const rats = ['Debra'];
diff --git a/test/unit/querystring-self-import/input.js b/test/unit/querystring-self-import/input.js
new file mode 100644
index 00000000..25f53ce9
--- /dev/null
+++ b/test/unit/querystring-self-import/input.js
@@ -0,0 +1,10 @@
+// Test that if a file and the same file with a querystring correspond to different
+// modules in memory, one can successfully import the other. The import chain
+// goes `input` (this file) -> `base?__withQuery` -> `base` -> `dep`, which means
+// that if `dep` shows up in `output`, we know that both `base?__withQuery` and
+// `base` have been loaded successfully.
+
+import * as baseWithQuery from './base?__withQuery';
+console.log('Dogs:', baseWithQuery.dogs);
+console.log('Cats:', baseWithQuery.cats);
+console.log('Rats:', baseWithQuery.rats);
diff --git a/test/unit/querystring-self-import/output.js b/test/unit/querystring-self-import/output.js
new file mode 100644
index 00000000..d6dc6b2c
--- /dev/null
+++ b/test/unit/querystring-self-import/output.js
@@ -0,0 +1,6 @@
+[
+  "package.json",
+  "test/unit/querystring-self-import/base.js",
+  "test/unit/querystring-self-import/dep.js",
+  "test/unit/querystring-self-import/input.js"
+]
diff --git a/tsconfig.json b/tsconfig.json
index 27218b7f..ab4973ca 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,7 +4,10 @@
     "esModuleInterop": true,
     "forceConsistentCasingInFileNames": true,
     "incremental": true,
-    "lib": ["esnext"],
+    "lib": [
+      "esnext",
+      "DOM" // needed for "new URL()"
+    ],
     "module": "commonjs",
     "moduleResolution": "node",
     "noEmitOnError": true,
@@ -21,4 +24,4 @@
   },
   "include": ["src/**/*"],
   "exclude": ["node_modules", "test/**/*"]
-}
\ No newline at end of file
+}