diff --git a/crates/ctap2-proto/src/authenticator/credential/make.rs b/crates/ctap2-proto/src/authenticator/credential/make.rs
index 809dd24..cd4630d 100644
--- a/crates/ctap2-proto/src/authenticator/credential/make.rs
+++ b/crates/ctap2-proto/src/authenticator/credential/make.rs
@@ -91,4 +91,7 @@ pub struct Response {
     /// > Contains the `largeBlobKey` for the credential, if requested with the
     /// > `largeBlobKey` extension.
     pub large_blob_key: Option<Vec<u8>>,
+    /// > A map, keyed by extension identifiers, to unsigned outputs of
+    /// > extensions, if any.
+    pub unsigned_extension_outputs: Option<HashMap<extension::Identifier, Vec<u8>>>,
 }