diff --git a/fido2/ctap.c b/fido2/ctap.c
index 3a46a65..05770c3 100644
--- a/fido2/ctap.c
+++ b/fido2/ctap.c
@@ -755,7 +755,7 @@ uint8_t ctap_make_credential(CborEncoder * encoder, uint8_t * request, int lengt
         }
     }
 
-    if (MC.up)
+    if (MC.up == 1 || MC.up == 0)
     {
         return CTAP2_ERR_INVALID_OPTION;
     }
@@ -1248,7 +1248,7 @@ uint8_t ctap_get_assertion(CborEncoder * encoder, uint8_t * request, int length)
     else
 #endif
     {
-        device_disable_up(!GA.up);
+        device_disable_up(GA.up == 0);
         ret = ctap_make_auth_data(&GA.rp, &map, auth_data_buf, &auth_data_buf_sz, NULL);
         device_disable_up(false);
         check_retr(ret);
diff --git a/fido2/ctap_parse.c b/fido2/ctap_parse.c
index 0825bba..9c155d2 100644
--- a/fido2/ctap_parse.c
+++ b/fido2/ctap_parse.c
@@ -715,6 +715,7 @@ uint8_t ctap_parse_make_credential(CTAP_makeCredential * MC, CborEncoder * encod
     CborValue it,map;
 
     memset(MC, 0, sizeof(CTAP_makeCredential));
+    MC->up = 0xff;
     ret = cbor_parser_init(request, length, CborValidateCanonicalFormat, &parser, &it);
     check_retr(ret);
 
@@ -1010,6 +1011,7 @@ uint8_t ctap_parse_get_assertion(CTAP_getAssertion * GA, uint8_t * request, int
 
     memset(GA, 0, sizeof(CTAP_getAssertion));
     GA->creds = getAssertionState.creds;     // Save stack memory
+    GA->up = 0xff;
 
     ret = cbor_parser_init(request, length, CborValidateCanonicalFormat, &parser, &it);
     check_ret(ret);