diff --git a/pkg/middleware/cors.go b/pkg/middleware/cors.go
new file mode 100644
index 0000000..c870d7c
--- /dev/null
+++ b/pkg/middleware/cors.go
@@ -0,0 +1 @@
+package middleware
diff --git a/pkg/session/session_reader.go b/pkg/session/session_reader.go
index 701a831..efb39dc 100644
--- a/pkg/session/session_reader.go
+++ b/pkg/session/session_reader.go
@@ -66,7 +66,7 @@ func (in *reader) getForTicket(ctx context.Context, ticket *Ticket) (*Session, e
 
 	data, err := encrypted.Decrypt(ticket.Crypter())
 	if err != nil {
-		return nil, fmt.Errorf("decrypting session data: %w", err)
+		return nil, fmt.Errorf("%w: decrypting session data: %w", ErrInvalid, err)
 	}
 
 	err = data.Validate()