diff --git a/include/psa/crypto_values.h b/include/psa/crypto_values.h
index 12358a1..b30f955 100644
--- a/include/psa/crypto_values.h
+++ b/include/psa/crypto_values.h
@@ -790,6 +790,9 @@
 #define PSA_ALG_IS_KEY_DERIVATION(alg)                                  \
     (((alg) & PSA_ALG_CATEGORY_MASK) == PSA_ALG_CATEGORY_KEY_DERIVATION)
 
+/** An invalid algorithm identifier value. */
+#define PSA_ALG_NONE                            ((psa_algorithm_t)0)
+
 #define PSA_ALG_HASH_MASK                       ((psa_algorithm_t)0x000000ff)
 /** MD2 */
 #define PSA_ALG_MD2                             ((psa_algorithm_t)0x02000001)
diff --git a/programs/psa/psa_constant_names_generated.c b/programs/psa/psa_constant_names_generated.c
index 590b000..de29716 100644
--- a/programs/psa/psa_constant_names_generated.c
+++ b/programs/psa/psa_constant_names_generated.c
@@ -221,6 +221,7 @@
     case PSA_ALG_MD2: append(&buffer, buffer_size, &required_size, "PSA_ALG_MD2", 11); break;
     case PSA_ALG_MD4: append(&buffer, buffer_size, &required_size, "PSA_ALG_MD4", 11); break;
     case PSA_ALG_MD5: append(&buffer, buffer_size, &required_size, "PSA_ALG_MD5", 11); break;
+    case PSA_ALG_NONE: append(&buffer, buffer_size, &required_size, "PSA_ALG_NONE", 12); break;
     case PSA_ALG_OFB: append(&buffer, buffer_size, &required_size, "PSA_ALG_OFB", 11); break;
     case PSA_ALG_PURE_EDDSA: append(&buffer, buffer_size, &required_size, "PSA_ALG_PURE_EDDSA", 18); break;
     case PSA_ALG_RIPEMD160: append(&buffer, buffer_size, &required_size, "PSA_ALG_RIPEMD160", 17); break;