diff --git a/types-use-ipfs-from-ts/src/main.ts b/types-use-ipfs-from-ts/src/main.ts
index 29e17416..5f84fd84 100644
--- a/types-use-ipfs-from-ts/src/main.ts
+++ b/types-use-ipfs-from-ts/src/main.ts
@@ -14,6 +14,7 @@ export default async function main() {
 
   console.log('Added file:', file.path, file.cid.toString())
   try {
+    // @ts-expect-error CID has no toUpperCase method 
     file.cid.toUpperCase()
   } catch (error) {
 
diff --git a/types-use-ipfs-from-typed-js/src/main.js b/types-use-ipfs-from-typed-js/src/main.js
index 5e245467..c5279b64 100644
--- a/types-use-ipfs-from-typed-js/src/main.js
+++ b/types-use-ipfs-from-typed-js/src/main.js
@@ -17,6 +17,7 @@ async function main () {
 
   console.log('Added file:', file.path, file.cid.toString())
   try {
+    // @ts-expect-error CID has no toUpperCase method 
     file.cid.toUpperCase()
   } catch(error) {