diff --git a/library/psa_crypto_mac.c b/library/psa_crypto_mac.c
index 9c44c23..6972472 100644
--- a/library/psa_crypto_mac.c
+++ b/library/psa_crypto_mac.c
@@ -195,6 +195,16 @@
                                 const uint8_t *key_buffer )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+#if defined(PSA_WANT_KEY_TYPE_DES)
+    /* Mbed TLS CMAC does not accept 3DES with only two keys, nor does it accept
+     * to do CMAC with pure DES, so return NOT_SUPPORTED here. */
+    if( psa_get_key_type( attributes ) == PSA_KEY_TYPE_DES &&
+        ( psa_get_key_bits( attributes ) == 64 ||
+          psa_get_key_bits( attributes ) == 128 ) )
+        return( PSA_ERROR_NOT_SUPPORTED );
+#endif
+
     const mbedtls_cipher_info_t * cipher_info =
         mbedtls_cipher_info_from_psa(
             PSA_ALG_CMAC,