diff --git a/hook.js b/hook.js
index 6f0adbd..b5d72f5 100644
--- a/hook.js
+++ b/hook.js
@@ -4,6 +4,7 @@
 
 const { URL } = require('url')
 const { inspect } = require('util')
+const { isIdentifierName } = require('@babel/helper-validator-identifier')
 const { builtinModules } = require('module')
 const specifiers = new Map()
 const isWin = process.platform === 'win32'
@@ -200,6 +201,10 @@ async function processModule ({ srcUrl, context, parentGetSource, parentResolve,
   const setters = new Map()
 
   const addSetter = (name, setter, isStarExport = false) => {
+    if (!isIdentifierName(name)) {
+      throw new Error(`'${name}' export is not a valid identifier name`)
+    }
+
     if (setters.has(name)) {
       if (isStarExport) {
         // If there's already a matching star export, delete it
@@ -380,7 +385,8 @@ function createHook (meta) {
     }
   }
 
-  async function getSource (url, context, parentGetSource) {
+  // For Node.js 16.12.0 and higher.
+  async function load (url, context, parentGetSource) {
     if (hasIitm(url)) {
       const realUrl = deleteIitm(url)
 
@@ -392,6 +398,8 @@ function createHook (meta) {
           parentResolve: cachedResolve
         })
         return {
+          shortCircuit: true,
+          format: 'module',
           source: `
 import { register } from '${iitmURL}'
 import * as namespace from ${JSON.stringify(realUrl)}
@@ -432,20 +440,6 @@ register(${JSON.stringify(realUrl)}, _, set, ${JSON.stringify(specifiers.get(rea
     return parentGetSource(url, context, parentGetSource)
   }
 
-  // For Node.js 16.12.0 and higher.
-  async function load (url, context, parentLoad) {
-    if (hasIitm(url)) {
-      const { source } = await getSource(url, context, parentLoad)
-      return {
-        source,
-        shortCircuit: true,
-        format: 'module'
-      }
-    }
-
-    return parentLoad(url, context, parentLoad)
-  }
-
   if (NODE_MAJOR >= 17 || (NODE_MAJOR === 16 && NODE_MINOR >= 12)) {
     return { initialize, load, resolve }
   } else {
@@ -453,7 +447,7 @@ register(${JSON.stringify(realUrl)}, _, set, ${JSON.stringify(specifiers.get(rea
       initialize,
       load,
       resolve,
-      getSource,
+      getSource: load,
       getFormat (url, context, parentGetFormat) {
         if (hasIitm(url)) {
           return {
diff --git a/package.json b/package.json
index 424b4e1..cfa5b8c 100644
--- a/package.json
+++ b/package.json
@@ -59,6 +59,7 @@
     "acorn": "^8.8.2",
     "acorn-import-attributes": "^1.9.5",
     "cjs-module-lexer": "^1.2.2",
-    "module-details-from-path": "^1.0.3"
+    "module-details-from-path": "^1.0.3",
+    "@babel/helper-validator-identifier": "^7.24.7"
   }
 }
diff --git a/test/fixtures/invalid-identifier.js b/test/fixtures/invalid-identifier.js
new file mode 100644
index 0000000..c604f80
--- /dev/null
+++ b/test/fixtures/invalid-identifier.js
@@ -0,0 +1 @@
+exports['one.two'] = () => console.log('b')
diff --git a/test/hook/invalid-identifier.mjs b/test/hook/invalid-identifier.mjs
new file mode 100644
index 0000000..6f4acf0
--- /dev/null
+++ b/test/hook/invalid-identifier.mjs
@@ -0,0 +1,4 @@
+import * as lib from '../fixtures/invalid-identifier.js'
+import { strictEqual } from 'assert'
+
+strictEqual(typeof lib['one.two'], 'function')