diff --git a/src/fido/cbor_get_info.c b/src/fido/cbor_get_info.c
index 9f0dd9e..bc5c5b3 100644
--- a/src/fido/cbor_get_info.c
+++ b/src/fido/cbor_get_info.c
@@ -26,7 +26,7 @@ int cbor_get_info() {
     CborEncoder encoder, mapEncoder, arrayEncoder, mapEncoder2;
     CborError error = CborNoError;
     cbor_encoder_init(&encoder, ctap_resp->init.data + 1, CTAP_MAX_PACKET_SIZE, 0);
-    CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, 13));
+    CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, 14));
 
     CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x01));
     CBOR_CHECK(cbor_encoder_create_array(&mapEncoder, &arrayEncoder, 3));
@@ -67,6 +67,9 @@ int cbor_get_info() {
     CBOR_CHECK(cbor_encode_boolean(&arrayEncoder, true));
     CBOR_CHECK(cbor_encoder_close_container(&mapEncoder, &arrayEncoder));
 
+    CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x05));
+    CBOR_CHECK(cbor_encode_uint(&mapEncoder, MAX_MSG_SIZE));
+
     CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x06));
     CBOR_CHECK(cbor_encoder_create_array(&mapEncoder, &arrayEncoder, 2));
     CBOR_CHECK(cbor_encode_uint(&arrayEncoder, 1)); // PIN protocols
diff --git a/src/fido/fido.h b/src/fido/fido.h
index df8e888..6eb90e8 100644
--- a/src/fido/fido.h
+++ b/src/fido/fido.h
@@ -79,6 +79,8 @@ extern void set_opts(uint8_t);
 #define MAX_CRED_ID_LENGTH        1024
 #define MAX_RESIDENT_CREDENTIALS  256
 #define MAX_CREDBLOB_LENGTH       128
+#define MAX_MSG_SIZE              1024
+#define MAX_FRAGMENT_LENGTH       (MAX_MSG_SIZE - 64)
 
 typedef struct known_app {
     const uint8_t *rp_id_hash;