diff --git a/matrix_sdk_crypto/src/file_encryption/attachments.rs b/matrix_sdk_crypto/src/file_encryption/attachments.rs
index de9ad6c1..4b6b7ea8 100644
--- a/matrix_sdk_crypto/src/file_encryption/attachments.rs
+++ b/matrix_sdk_crypto/src/file_encryption/attachments.rs
@@ -133,7 +133,7 @@ impl<'a, R: Read + 'a> AttachmentEncryptor<'a, R> {
         };
         let encoded_iv = encode(iv);
 
-        let aes = Aes256Ctr::new_var(&key, &iv).unwrap();
+        let aes = Aes256Ctr::new_var(&key, &iv).expect("Cannot create AES encryption object.");
 
         AttachmentEncryptor {
             finished: false,