diff --git a/.changeset/mighty-bulldogs-begin.md b/.changeset/mighty-bulldogs-begin.md
new file mode 100644
index 0000000000..b2623ab7c8
--- /dev/null
+++ b/.changeset/mighty-bulldogs-begin.md
@@ -0,0 +1,5 @@
+---
+'@rrweb/web-extension': patch
+---
+
+Update `vite.config.ts` to account for all potential entry types.
diff --git a/packages/web-extension/vite.config.ts b/packages/web-extension/vite.config.ts
index 95809cb727..76d2c631a3 100644
--- a/packages/web-extension/vite.config.ts
+++ b/packages/web-extension/vite.config.ts
@@ -1,9 +1,4 @@
-import {
-  defineConfig,
-  LibraryFormats,
-  LibraryOptions,
-  PluginOption,
-} from 'vite';
+import { defineConfig, LibraryFormats, PluginOption } from 'vite';
 import webExtension, { readJsonFile } from 'vite-plugin-web-extension';
 import zip from 'vite-plugin-zip-pack';
 import * as path from 'path';
@@ -17,9 +12,19 @@ function useSpecialFormat(
   return {
     name: 'use-special-format',
     config(config) {
-      const shouldUse = entriesToUse.includes(
-        (config.build?.lib as LibraryOptions)?.entry,
-      );
+      // entry can be string | string[] | {[entryAlias: string]: string}
+      const entry = config.build?.lib && config.build.lib.entry;
+      let shouldUse = false;
+
+      if (typeof entry === 'string') {
+        shouldUse = entriesToUse.includes(entry);
+      } else if (Array.isArray(entry)) {
+        shouldUse = entriesToUse.some((e) => entry.includes(e));
+      } else if (entry && typeof entry === 'object') {
+        const entryKeys = Object.keys(entry);
+        shouldUse = entriesToUse.some((e) => entryKeys.includes(e));
+      }
+
       if (shouldUse) {
         config.build = config.build ?? {};
         // @ts-expect-error: lib needs to be an object, forcing it.