diff --git a/web-client/src/applicationContext.ts b/web-client/src/applicationContext.ts
index a23143e4caa..a7d48508406 100644
--- a/web-client/src/applicationContext.ts
+++ b/web-client/src/applicationContext.ts
@@ -363,6 +363,39 @@ const reduce = ImageBlobReduce({
 
 let user;
 let broadcastChannel;
+const clientSupportsES2022 = (() => {
+  try {
+    // Check Object.hasOwn (introduced in ES2022)
+    // @ts-ignore
+    if (typeof Object.hasOwn !== 'function') {
+      return false;
+    }
+
+    // Check Array.prototype.at
+    if (!Array.prototype.at) {
+      return false;
+    }
+
+    // Check private fields
+    class TestPrivateFields {
+      #privateField: boolean;
+      constructor() {
+        this.#privateField = true;
+      }
+      hasPrivateField() {
+        return this.#privateField;
+      }
+    }
+    const instance = new TestPrivateFields();
+    if (!instance.hasPrivateField()) {
+      return false;
+    }
+
+    return true;
+  } catch (e) {
+    return false; // Any failure indicates lack of support
+  }
+})();
 
 let forceRefreshCallback: () => {};
 
@@ -671,9 +704,19 @@ const applicationContext = {
     },
   }),
   getPdfJs: async () => {
-    const pdfjsLib = (await import('pdfjs-dist')).default;
-    const pdfjsWorker = (await import('pdfjs-dist/build/pdf.worker.entry'))
-      .default;
+    const pdfjsLib = (
+      await import(
+        clientSupportsES2022 ? 'pdfjs-dist' : 'pdfjs-dist/legacy/build/pdf'
+      )
+    ).default;
+    const pdfjsWorker = (
+      await import(
+        clientSupportsES2022
+          ? 'pdfjs-dist/build/pdf.worker.entry'
+          : 'pdfjs-dist/legacy/build/pdf.worker.entry'
+      )
+    ).default;
+
     pdfjsLib.GlobalWorkerOptions.workerSrc = pdfjsWorker;
     return pdfjsLib;
   },