diff --git a/src/RootApp.tsx b/src/RootApp.tsx
index ebfebc4252..5a0497d9d7 100644
--- a/src/RootApp.tsx
+++ b/src/RootApp.tsx
@@ -18,7 +18,9 @@ const RootApp = () => (
                 </WebConfigProvider>
             </UserSettingsProvider>
         </ApiProvider>
-        <ReactQueryDevtools initialIsOpen={false} />
+        {window.Proxy && ( // '@tanstack/query-devtools' requires 'Proxy', which cannot be polyfilled for legacy browsers
+            <ReactQueryDevtools initialIsOpen={false} />
+        )}
     </QueryClientProvider>
 );
 
diff --git a/webpack.common.js b/webpack.common.js
index efda98699a..734343813d 100644
--- a/webpack.common.js
+++ b/webpack.common.js
@@ -230,6 +230,23 @@ const config = {
                     }
                 }]
             },
+            // Strict EcmaScript modules require additional flags
+            {
+                test: /\.(js|jsx|mjs)$/,
+                include: [
+                    path.resolve(__dirname, 'node_modules/@tanstack/query-devtools')
+                ],
+                resolve: {
+                    fullySpecified: false
+                },
+                use: [{
+                    loader: 'babel-loader',
+                    options: {
+                        cacheCompression: false,
+                        cacheDirectory: true
+                    }
+                }]
+            },
             {
                 test: /\.worker\.ts$/,
                 exclude: /node_modules/,