diff --git a/packages/playwright-core/src/utils/index.ts b/packages/playwright-core/src/utils/index.ts
index a5219cda6c..67ec09d91d 100644
--- a/packages/playwright-core/src/utils/index.ts
+++ b/packages/playwright-core/src/utils/index.ts
@@ -26,7 +26,7 @@ export * from './headers';
 export * from './hostPlatform';
 export * from './httpServer';
 export * from './manualPromise';
-export * from './mimeType';
+export * from './isomorphic/mimeType';
 export * from './multimap';
 export * from './network';
 export * from './processLauncher';
diff --git a/packages/playwright-core/src/utils/mimeType.ts b/packages/playwright-core/src/utils/isomorphic/mimeType.ts
similarity index 100%
rename from packages/playwright-core/src/utils/mimeType.ts
rename to packages/playwright-core/src/utils/isomorphic/mimeType.ts
diff --git a/packages/trace-viewer/src/ui/attachmentsTab.tsx b/packages/trace-viewer/src/ui/attachmentsTab.tsx
index 86d80fe387..7b97513c2d 100644
--- a/packages/trace-viewer/src/ui/attachmentsTab.tsx
+++ b/packages/trace-viewer/src/ui/attachmentsTab.tsx
@@ -21,12 +21,7 @@ import type { MultiTraceModel } from './modelUtil';
 import { PlaceholderPanel } from './placeholderPanel';
 import type { AfterActionTraceEventAttachment } from '@trace/trace';
 
-// TODO: remove local function and restore import
-// import { isTextualMimeType } from 'playwright-core/lib/utils';
-
-function isTextualMimeType(mimeType: string) {
-  return !!mimeType.match(/^(text\/.*?|application\/(json|(x-)?javascript|xml.*?|ecmascript|graphql|x-www-form-urlencoded)|image\/svg(\+xml)?|application\/.*?(\+json|\+xml))(;\s*charset=.*)?$/);
-}
+import { isTextualMimeType } from '@isomorphic/mimeType';
 
 
 type Attachment = AfterActionTraceEventAttachment & { traceUrl: string };