diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 4814d50f89..05f9d9de42 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -1578,11 +1578,14 @@
  * Requires: MBEDTLS_SSL_KEEP_PEER_CERTIFICATE
  * Requires: MBEDTLS_PSA_CRYPTO_C
  *
- * Note: even though TLS 1.3 depends on PSA Crypto, and uses it unconditionally
- * for most operations, if you want it to only use PSA for all crypto
- * operations, you need to also enable MBEDTLS_USE_PSA_CRYPTO; otherwise X.509
- * operations, and functions that are common with TLS 1.2 (record protection,
- * running handshake hash) will still use non-PSA crypto.
+ * \note TLS 1.3 uses PSA crypto for cryptographic operations that are
+ *       directly performed by TLS 1.3 code. As a consequence, you must
+ *       call psa_crypto_init() before the first TLS 1.3 handshake.
+ *
+ * \note Cryptographic operations performed indirectly via another module
+ *       (X.509, PK) or by code shared with TLS 1.2 (record protection,
+ *       running handshake hash) only use PSA crypto if
+ *       #MBEDTLS_USE_PSA_CRYPTO is enabled.
  *
  * Uncomment this macro to enable the support for TLS 1.3.
  */
@@ -1651,45 +1654,6 @@
  */
 #define MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED
 
-/**
- * \def MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE
- *
- * Maximum time difference in milliseconds tolerated between the age of a
- * ticket from the server and client point of view.
- * From the client point of view, the age of a ticket is the time difference
- * between the time when the client proposes to the server to use the ticket
- * (time of writing of the Pre-Shared Key Extension including the ticket) and
- * the time the client received the ticket from the server.
- * From the server point of view, the age of a ticket is the time difference
- * between the time when the server receives a proposition from the client
- * to use the ticket and the time when the ticket was created by the server.
- * The server age is expected to be always greater than the client one and
- * MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE defines the
- * maximum difference tolerated for the server to accept the ticket.
- * This is not used in TLS 1.2.
- *
- */
-#define MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE 6000
-
-/**
- * \def MBEDTLS_SSL_TLS1_3_TICKET_NONCE_LENGTH
- *
- * Size in bytes of a ticket nonce. This is not used in TLS 1.2.
- *
- * This must be less than 256.
- */
-#define MBEDTLS_SSL_TLS1_3_TICKET_NONCE_LENGTH 32
-
-/**
- * \def MBEDTLS_SSL_TLS1_3_DEFAULT_NEW_SESSION_TICKETS
- *
- * Default number of NewSessionTicket messages to be sent by a TLS 1.3 server
- * after handshake completion. This is not used in TLS 1.2 and relevant only if
- * the MBEDTLS_SSL_SESSION_TICKETS option is enabled.
- *
- */
-#define MBEDTLS_SSL_TLS1_3_DEFAULT_NEW_SESSION_TICKETS 1
-
 /**
  * \def MBEDTLS_SSL_EARLY_DATA
  *
@@ -3843,6 +3807,45 @@
  */
 //#define MBEDTLS_SSL_CIPHERSUITES MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
 
+/**
+ * \def MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE
+ *
+ * Maximum time difference in milliseconds tolerated between the age of a
+ * ticket from the server and client point of view.
+ * From the client point of view, the age of a ticket is the time difference
+ * between the time when the client proposes to the server to use the ticket
+ * (time of writing of the Pre-Shared Key Extension including the ticket) and
+ * the time the client received the ticket from the server.
+ * From the server point of view, the age of a ticket is the time difference
+ * between the time when the server receives a proposition from the client
+ * to use the ticket and the time when the ticket was created by the server.
+ * The server age is expected to be always greater than the client one and
+ * MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE defines the
+ * maximum difference tolerated for the server to accept the ticket.
+ * This is not used in TLS 1.2.
+ *
+ */
+#define MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE 6000
+
+/**
+ * \def MBEDTLS_SSL_TLS1_3_TICKET_NONCE_LENGTH
+ *
+ * Size in bytes of a ticket nonce. This is not used in TLS 1.2.
+ *
+ * This must be less than 256.
+ */
+#define MBEDTLS_SSL_TLS1_3_TICKET_NONCE_LENGTH 32
+
+/**
+ * \def MBEDTLS_SSL_TLS1_3_DEFAULT_NEW_SESSION_TICKETS
+ *
+ * Default number of NewSessionTicket messages to be sent by a TLS 1.3 server
+ * after handshake completion. This is not used in TLS 1.2 and relevant only if
+ * the MBEDTLS_SSL_SESSION_TICKETS option is enabled.
+ *
+ */
+#define MBEDTLS_SSL_TLS1_3_DEFAULT_NEW_SESSION_TICKETS 1
+
 /* X509 options */
 //#define MBEDTLS_X509_MAX_INTERMEDIATE_CA   8   /**< Maximum number of intermediate CAs in a verification chain. */
 //#define MBEDTLS_X509_MAX_FILE_PATH_LEN     512 /**< Maximum length of a path/filename string in bytes including the null terminator character ('\0'). */
diff --git a/include/mbedtls/pk.h b/include/mbedtls/pk.h
index 0e4ee38440..3de7a8fa04 100644
--- a/include/mbedtls/pk.h
+++ b/include/mbedtls/pk.h
@@ -796,6 +796,10 @@ static inline mbedtls_ecp_keypair *mbedtls_pk_ec(const mbedtls_pk_context pk)
 /**
  * \brief           Parse a private key in PEM or DER format
  *
+ * \note            If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                  subsystem must have been initialized by calling
+ *                  psa_crypto_init() before calling this function.
+ *
  * \param ctx       The PK context to fill. It must have been initialized
  *                  but not set up.
  * \param key       Input buffer to parse.
@@ -832,6 +836,10 @@ int mbedtls_pk_parse_key(mbedtls_pk_context *ctx,
 /**
  * \brief           Parse a public key in PEM or DER format
  *
+ * \note            If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                  subsystem must have been initialized by calling
+ *                  psa_crypto_init() before calling this function.
+ *
  * \param ctx       The PK context to fill. It must have been initialized
  *                  but not set up.
  * \param key       Input buffer to parse.
@@ -861,6 +869,10 @@ int mbedtls_pk_parse_public_key(mbedtls_pk_context *ctx,
 /**
  * \brief           Load and parse a private key
  *
+ * \note            If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                  subsystem must have been initialized by calling
+ *                  psa_crypto_init() before calling this function.
+ *
  * \param ctx       The PK context to fill. It must have been initialized
  *                  but not set up.
  * \param path      filename to read the private key from
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 4b954bb458..29ba85a397 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1869,6 +1869,10 @@ void mbedtls_ssl_init(mbedtls_ssl_context *ssl);
  *                 Calling mbedtls_ssl_setup again is not supported, even
  *                 if no session is active.
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param ssl      SSL context
  * \param conf     SSL configuration to use
  *
@@ -4684,6 +4688,11 @@ int mbedtls_ssl_get_session(const mbedtls_ssl_context *ssl,
  *                 in which case the datagram of the underlying transport that is
  *                 currently being processed might or might not contain further
  *                 DTLS records.
+ *
+ * \note           If the context is configured to allow TLS 1.3, or if
+ *                 #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
  */
 int mbedtls_ssl_handshake(mbedtls_ssl_context *ssl);
 
diff --git a/include/mbedtls/x509_crl.h b/include/mbedtls/x509_crl.h
index 49bbf61647..62694ae7fb 100644
--- a/include/mbedtls/x509_crl.h
+++ b/include/mbedtls/x509_crl.h
@@ -107,6 +107,10 @@ mbedtls_x509_crl;
 /**
  * \brief          Parse a DER-encoded CRL and append it to the chained list
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param chain    points to the start of the chain
  * \param buf      buffer holding the CRL data in DER format
  * \param buflen   size of the buffer
@@ -121,6 +125,10 @@ int mbedtls_x509_crl_parse_der(mbedtls_x509_crl *chain,
  *
  * \note           Multiple CRLs are accepted only if using PEM format
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param chain    points to the start of the chain
  * \param buf      buffer holding the CRL data in PEM or DER format
  * \param buflen   size of the buffer
@@ -136,6 +144,10 @@ int mbedtls_x509_crl_parse(mbedtls_x509_crl *chain, const unsigned char *buf, si
  *
  * \note           Multiple CRLs are accepted only if using PEM format
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param chain    points to the start of the chain
  * \param path     filename to read the CRLs from (in PEM or DER encoding)
  *
diff --git a/include/mbedtls/x509_crt.h b/include/mbedtls/x509_crt.h
index 036282f7c9..11e5951f60 100644
--- a/include/mbedtls/x509_crt.h
+++ b/include/mbedtls/x509_crt.h
@@ -341,6 +341,10 @@ extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_none;
  * \brief          Parse a single DER formatted certificate and add it
  *                 to the end of the provided chained list.
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param chain    The pointer to the start of the CRT chain to attach to.
  *                 When parsing the first CRT in a chain, this should point
  *                 to an instance of ::mbedtls_x509_crt initialized through
@@ -402,6 +406,10 @@ typedef int (*mbedtls_x509_crt_ext_cb_t)(void *p_ctx,
  * \brief            Parse a single DER formatted certificate and add it
  *                   to the end of the provided chained list.
  *
+ * \note             If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                   subsystem must have been initialized by calling
+ *                   psa_crypto_init() before calling this function.
+ *
  * \param chain      The pointer to the start of the CRT chain to attach to.
  *                   When parsing the first CRT in a chain, this should point
  *                   to an instance of ::mbedtls_x509_crt initialized through
@@ -452,6 +460,10 @@ int mbedtls_x509_crt_parse_der_with_ext_cb(mbedtls_x509_crt *chain,
  *                 temporary ownership of the CRT buffer until the CRT
  *                 is destroyed.
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param chain    The pointer to the start of the CRT chain to attach to.
  *                 When parsing the first CRT in a chain, this should point
  *                 to an instance of ::mbedtls_x509_crt initialized through
@@ -492,6 +504,10 @@ int mbedtls_x509_crt_parse_der_nocopy(mbedtls_x509_crt *chain,
  *                 long as the certificates are enclosed in the PEM specific
  *                 '-----{BEGIN/END} CERTIFICATE-----' delimiters.
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param chain    The chain to which to add the parsed certificates.
  * \param buf      The buffer holding the certificate data in PEM or DER format.
  *                 For certificates in PEM encoding, this may be a concatenation
@@ -516,6 +532,10 @@ int mbedtls_x509_crt_parse(mbedtls_x509_crt *chain, const unsigned char *buf, si
  *                 of failed certificates it encountered. If none complete
  *                 correctly, the first error is returned.
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param chain    points to the start of the chain
  * \param path     filename to read the certificates from
  *
diff --git a/include/mbedtls/x509_csr.h b/include/mbedtls/x509_csr.h
index 0c204be067..e376000a40 100644
--- a/include/mbedtls/x509_csr.h
+++ b/include/mbedtls/x509_csr.h
@@ -89,6 +89,10 @@ mbedtls_x509write_csr;
  *
  * \note           CSR attributes (if any) are currently silently ignored.
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param csr      CSR context to fill
  * \param buf      buffer holding the CRL data
  * \param buflen   size of the buffer
@@ -103,6 +107,10 @@ int mbedtls_x509_csr_parse_der(mbedtls_x509_csr *csr,
  *
  * \note           See notes for \c mbedtls_x509_csr_parse_der()
  *
+ * \note           If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ *                 subsystem must have been initialized by calling
+ *                 psa_crypto_init() before calling this function.
+ *
  * \param csr      CSR context to fill
  * \param buf      buffer holding the CRL data
  * \param buflen   size of the buffer