diff --git a/include/mbedtls/build_info.h b/include/mbedtls/build_info.h
index 234debd..6195ac9 100644
--- a/include/mbedtls/build_info.h
+++ b/include/mbedtls/build_info.h
@@ -77,7 +77,11 @@
 #if defined(MBEDTLS_PK_C) && defined(MBEDTLS_USE_PSA_CRYPTO)
 #define MBEDTLS_PK_WRITE_C
 #endif
-#if defined(MBEDTLS_PSA_CRYPTO_CONFIG)
+
+/* Make sure all configuration symbols are set before including check_config.h,
+ * even the ones that are calculated programmatically. */
+#if defined(MBEDTLS_PSA_CRYPTO_CONFIG) /* PSA_WANT_xxx influences MBEDTLS_xxx */ || \
+    defined(MBEDTLS_PSA_CRYPTO_C) /* MBEDTLS_xxx influences PSA_WANT_xxx */
 #include "mbedtls/config_psa.h"
 #endif
 
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index e00ffb5..fa70058 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -750,18 +750,29 @@
 #error "MBEDTLS_SSL_PROTO_TLS1_2 defined, but not all prerequisites"
 #endif
 
-/*
- * HKDF is mandatory for TLS 1.3.
- * Otherwise support for at least one ciphersuite mandates either SHA_256 or
- * SHA_384.
- */
+/* TLS 1.3 requires separate HKDF parts from PSA */
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3) && \
-    ( ( !defined(MBEDTLS_HKDF_C) ) || \
-      ( !defined(MBEDTLS_SHA256_C) && !defined(MBEDTLS_SHA384_C) ) || \
-      ( !defined(MBEDTLS_PSA_CRYPTO_C) ) )
+        !( defined(MBEDTLS_PSA_CRYPTO_C) && defined(PSA_WANT_ALG_HKDF_EXTRACT) && defined(PSA_WANT_ALG_HKDF_EXPAND) )
 #error "MBEDTLS_SSL_PROTO_TLS1_3 defined, but not all prerequisites"
 #endif
 
+/* TLS 1.3 requires at least one ciphersuite, so at least SHA-256 or SHA-384 */
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
+/* We always need at least one of the hashes via PSA (for use with HKDF) */
+#if !( defined(PSA_WANT_ALG_SHA_256) || defined(PSA_WANT_ALG_SHA_384) )
+#error "MBEDTLS_SSL_PROTO_TLS1_3 defined, but not all prerequisites"
+#endif /* !(PSA_WANT_ALG_SHA_256 || PSA_WANT_ALG_SHA_384) */
+#if !defined(MBEDTLS_USE_PSA_CRYPTO)
+/* When USE_PSA_CRYPTO is not defined, we also need SHA-256 or SHA-384 via the
+ * legacy interface, including via the MD layer, for the parts of the code
+ * that are shared with TLS 1.2 (running handshake hash). */
+#if !defined(MBEDTLS_MD_C) || \
+    !( defined(MBEDTLS_SHA256_C) || defined(MBEDTLS_SHA384_C) )
+#error "MBEDTLS_SSL_PROTO_TLS1_3 defined, but not all prerequisites"
+#endif /* !MBEDTLS_MD_C || !(MBEDTLS_SHA256_C || MBEDTLS_SHA384_C) */
+#endif /* !MBEDTLS_USE_PSA_CRYPTO */
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
+
 /*
  * The current implementation of TLS 1.3 requires MBEDTLS_SSL_KEEP_PEER_CERTIFICATE.
  */
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 3d820a5..1e0220a 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -338,11 +338,11 @@
 #define MBEDTLS_SSL_SRV_CIPHERSUITE_ORDER_SERVER  0
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3) && defined(MBEDTLS_SSL_SESSION_TICKETS)
-#if defined(MBEDTLS_SHA384_C)
+#if defined(PSA_WANT_ALG_SHA_384)
 #define MBEDTLS_SSL_TLS1_3_TICKET_RESUMPTION_KEY_LEN        48
-#elif defined(MBEDTLS_SHA256_C)
+#elif defined(PSA_WANT_ALG_SHA_256)
 #define MBEDTLS_SSL_TLS1_3_TICKET_RESUMPTION_KEY_LEN        32
-#endif /* MBEDTLS_SHA256_C  */
+#endif
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 && MBEDTLS_SSL_SESSION_TICKETS */
 /*
  * Default range for DTLS retransmission timer value, in milliseconds.
@@ -629,7 +629,12 @@
 
 #define MBEDTLS_PREMASTER_SIZE     sizeof( union mbedtls_ssl_premaster_secret )
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#define MBEDTLS_TLS1_3_MD_MAX_SIZE         PSA_HASH_MAX_SIZE
+#else
 #define MBEDTLS_TLS1_3_MD_MAX_SIZE         MBEDTLS_MD_MAX_SIZE
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
 
 /* Length in number of bytes of the TLS sequence number */
 #define MBEDTLS_SSL_SEQUENCE_NUMBER_LEN 8
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 4842135..a59e672 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -2137,33 +2137,33 @@
     switch( sig_alg )
     {
 #if defined(MBEDTLS_ECDSA_C)
-#if defined(MBEDTLS_SHA256_C) && defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
+#if defined(PSA_WANT_ALG_SHA_256) && defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
         case MBEDTLS_TLS1_3_SIG_ECDSA_SECP256R1_SHA256:
             break;
-#endif /* MBEDTLS_SHA256_C && MBEDTLS_ECP_DP_SECP256R1_ENABLED */
-#if defined(MBEDTLS_SHA384_C) && defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED)
+#endif /* PSA_WANT_ALG_SHA_256 && MBEDTLS_ECP_DP_SECP256R1_ENABLED */
+#if defined(PSA_WANT_ALG_SHA_384) && defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED)
         case MBEDTLS_TLS1_3_SIG_ECDSA_SECP384R1_SHA384:
             break;
-#endif /* MBEDTLS_SHA384_C && MBEDTLS_ECP_DP_SECP384R1_ENABLED */
-#if defined(MBEDTLS_SHA512_C) && defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED)
+#endif /* PSA_WANT_ALG_SHA_384 && MBEDTLS_ECP_DP_SECP384R1_ENABLED */
+#if defined(PSA_WANT_ALG_SHA_512) && defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED)
         case MBEDTLS_TLS1_3_SIG_ECDSA_SECP521R1_SHA512:
             break;
-#endif /* MBEDTLS_SHA512_C && MBEDTLS_ECP_DP_SECP521R1_ENABLED */
+#endif /* PSA_WANT_ALG_SHA_512 && MBEDTLS_ECP_DP_SECP521R1_ENABLED */
 #endif /* MBEDTLS_ECDSA_C */
 
 #if defined(MBEDTLS_PKCS1_V21)
-#if defined(MBEDTLS_SHA256_C)
+#if defined(PSA_WANT_ALG_SHA_256)
         case MBEDTLS_TLS1_3_SIG_RSA_PSS_RSAE_SHA256:
             break;
-#endif /* MBEDTLS_SHA256_C  */
-#if defined(MBEDTLS_SHA384_C)
+#endif /* PSA_WANT_ALG_SHA_256  */
+#if defined(PSA_WANT_ALG_SHA_384)
         case MBEDTLS_TLS1_3_SIG_RSA_PSS_RSAE_SHA384:
             break;
-#endif /* MBEDTLS_SHA384_C */
-#if defined(MBEDTLS_SHA512_C)
+#endif /* PSA_WANT_ALG_SHA_384 */
+#if defined(PSA_WANT_ALG_SHA_512)
         case MBEDTLS_TLS1_3_SIG_RSA_PSS_RSAE_SHA512:
             break;
-#endif /* MBEDTLS_SHA512_C */
+#endif /* PSA_WANT_ALG_SHA_512 */
 #endif /* MBEDTLS_PKCS1_V21 */
         default:
             return( 0 );
@@ -2178,18 +2178,18 @@
     switch( sig_alg )
     {
 #if defined(MBEDTLS_PKCS1_V15)
-#if defined(MBEDTLS_SHA256_C)
+#if defined(MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA)
         case MBEDTLS_TLS1_3_SIG_RSA_PKCS1_SHA256:
             break;
-#endif /* MBEDTLS_SHA256_C */
-#if defined(MBEDTLS_SHA384_C)
+#endif /* MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA */
+#if defined(MBEDTLS_HAS_ALG_SHA_384_VIA_MD_OR_PSA_BASED_ON_USE_PSA)
         case MBEDTLS_TLS1_3_SIG_RSA_PKCS1_SHA384:
             break;
-#endif /* MBEDTLS_SHA384_C */
-#if defined(MBEDTLS_SHA512_C)
+#endif /* MBEDTLS_HAS_ALG_SHA_384_VIA_MD_OR_PSA_BASED_ON_USE_PSA */
+#if defined(MBEDTLS_HAS_ALG_SHA_512_VIA_MD_OR_PSA_BASED_ON_USE_PSA)
         case MBEDTLS_TLS1_3_SIG_RSA_PKCS1_SHA512:
             break;
-#endif /* MBEDTLS_SHA512_C */
+#endif /* MBEDTLS_HAS_ALG_SHA_512_VIA_MD_OR_PSA_BASED_ON_USE_PSA */
 #endif /* MBEDTLS_PKCS1_V15 */
         default:
             return( mbedtls_ssl_tls13_sig_alg_for_cert_verify_is_supported(
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 2b9ac5c..6f60fab 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -976,7 +976,7 @@
     psa_algorithm_t psa_algorithm = PSA_ALG_NONE;
     uint16_t algorithm = MBEDTLS_TLS1_3_SIG_NONE;
     size_t signature_len = 0;
-    unsigned char verify_hash[ MBEDTLS_MD_MAX_SIZE ];
+    unsigned char verify_hash[PSA_HASH_MAX_SIZE];
     size_t verify_hash_len;
     psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
 
@@ -1361,7 +1361,7 @@
 int mbedtls_ssl_reset_transcript_for_hrr( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    unsigned char hash_transcript[ MBEDTLS_MD_MAX_SIZE + 4 ];
+    unsigned char hash_transcript[PSA_HASH_MAX_SIZE + 4];
     size_t hash_len;
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
     uint16_t cipher_suite = ssl->session_negotiate->ciphersuite;
@@ -1371,7 +1371,7 @@
 
     ret = mbedtls_ssl_get_handshake_transcript( ssl, ciphersuite_info->mac,
                                                 hash_transcript + 4,
-                                                MBEDTLS_MD_MAX_SIZE,
+                                                PSA_HASH_MAX_SIZE,
                                                 &hash_len );
     if( ret != 0 )
     {
@@ -1386,9 +1386,9 @@
 
     hash_len += 4;
 
+#if defined(MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA)
     if( ciphersuite_info->mac == MBEDTLS_MD_SHA256 )
     {
-#if defined(MBEDTLS_SHA256_C)
         MBEDTLS_SSL_DEBUG_BUF( 4, "Truncated SHA-256 handshake transcript",
                                hash_transcript, hash_len );
 
@@ -1398,11 +1398,11 @@
 #else
         mbedtls_sha256_starts( &ssl->handshake->fin_sha256, 0 );
 #endif
-#endif /* MBEDTLS_SHA256_C */
     }
-    else if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 )
+#endif /* MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA */
+#if defined(MBEDTLS_HAS_ALG_SHA_384_VIA_MD_OR_PSA_BASED_ON_USE_PSA)
+    if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 )
     {
-#if defined(MBEDTLS_SHA384_C)
         MBEDTLS_SSL_DEBUG_BUF( 4, "Truncated SHA-384 handshake transcript",
                                hash_transcript, hash_len );
 
@@ -1412,12 +1412,11 @@
 #else
         mbedtls_sha512_starts( &ssl->handshake->fin_sha384, 1 );
 #endif
-#endif /* MBEDTLS_SHA384_C */
     }
-
-#if defined(MBEDTLS_SHA256_C) || defined(MBEDTLS_SHA384_C)
+#endif /* MBEDTLS_HAS_ALG_SHA_384_VIA_MD_OR_PSA_BASED_ON_USE_PSA */
+#if defined(MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA) || defined(MBEDTLS_HAS_ALG_SHA_384_VIA_MD_OR_PSA_BASED_ON_USE_PSA)
     ssl->handshake->update_checksum( ssl, hash_transcript, hash_len );
-#endif /* MBEDTLS_SHA256_C || MBEDTLS_SHA384_C */
+#endif /* MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA || MBEDTLS_HAS_ALG_SHA_384_VIA_MD_OR_PSA_BASED_ON_USE_PSA */
 
     return( ret );
 }
diff --git a/library/ssl_tls13_keys.h b/library/ssl_tls13_keys.h
index b1155fb..d82bf7a 100644
--- a/library/ssl_tls13_keys.h
+++ b/library/ssl_tls13_keys.h
@@ -81,7 +81,7 @@
  * Since contexts are always hashes of message transcripts, this can
  * be approximated from above by the maximum hash size. */
 #define MBEDTLS_SSL_TLS1_3_KEY_SCHEDULE_MAX_CONTEXT_LEN  \
-    MBEDTLS_MD_MAX_SIZE
+    PSA_HASH_MAX_SIZE
 
 /* Maximum desired length for expanded key material generated
  * by HKDF-Expand-Label.
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 6c70f78..0752f7b 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -1870,8 +1870,10 @@
     scripts/config.py unset MBEDTLS_HMAC_DRBG_C
     scripts/config.py unset MBEDTLS_ECDSA_DETERMINISTIC
     scripts/config.py -f include/psa/crypto_config.h unset PSA_WANT_ALG_DETERMINISTIC_ECDSA
-    # TLS 1.3 currently depends on SHA256_C || SHA384_C
-    # but is already disabled in the default config
+    # Enable TLS 1.3: use PSA implementation for hashes
+    scripts/config.py set MBEDTLS_SSL_PROTO_TLS1_3
+    scripts/config.py set MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
+    scripts/config.py set MBEDTLS_SSL_CID_TLS1_3_PADDING_GRANULARITY 1
 
     loc_accel_flags="$loc_accel_flags $( echo "$loc_accel_list" | sed 's/[^ ]* */-DMBEDTLS_PSA_ACCEL_&/g' )"
     make CFLAGS="$ASAN_CFLAGS -Werror -I../tests/include -I../tests -I../../tests -DPSA_CRYPTO_DRIVER_TEST -DMBEDTLS_TEST_LIBTESTDRIVER1 $loc_accel_flags" LDFLAGS="-ltestdriver1 $ASAN_CFLAGS" all