diff --git a/targets/stm32l432/src/nfc.c b/targets/stm32l432/src/nfc.c
index 0c2b3a6..3590d5d 100644
--- a/targets/stm32l432/src/nfc.c
+++ b/targets/stm32l432/src/nfc.c
@@ -208,10 +208,13 @@ void nfc_process_iblock(uint8_t * buf, int len)
         case APDU_FIDO_U2F_REGISTER:
 			printf1(TAG_NFC, "U2F Register command.\r\n");
 
+			nfc_write_response(buf[0], SW_COND_USE_NOT_SATISFIED);
         break;
 
         case APDU_FIDO_U2F_AUTHENTICATE:
 			printf1(TAG_NFC, "U2F Authenticate command.\r\n");
+			
+			nfc_write_response(buf[0], SW_COND_USE_NOT_SATISFIED);
         break;
 
         case APDU_FIDO_NFCCTAP_MSG:
diff --git a/targets/stm32l432/src/nfc.h b/targets/stm32l432/src/nfc.h
index 803bf26..d80155a 100644
--- a/targets/stm32l432/src/nfc.h
+++ b/targets/stm32l432/src/nfc.h
@@ -67,6 +67,7 @@ typedef enum
 } APPLETS;
 
 #define SW_SUCCESS                    0x9000
+#define SW_COND_USE_NOT_SATISFIED     0x6985
 #define SW_FILE_NOT_FOUND             0x6a82
 #define SW_INS_INVALID                0x6d00
 #define SW_INTERNAL_EXCEPTION         0x6f00