diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index a5b414e97..a10e59bbc 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1674,6 +1674,10 @@ static int ssl_tls13_write_key_share_ext( mbedtls_ssl_context *ssl,
 
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding key share extension" ) );
 
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "server hello, write selected_group: %s (%04x)",
+                                mbedtls_ssl_named_group_to_str( group ),
+                                group ) );
+
     /* Check if we have space for header and length fields:
      * - extension_type         (2 bytes)
      * - extension_data_length  (2 bytes)
diff --git a/tests/opt-testcases/tls13-kex-modes.sh b/tests/opt-testcases/tls13-kex-modes.sh
index 70a60672b..af2a42d02 100755
--- a/tests/opt-testcases/tls13-kex-modes.sh
+++ b/tests/opt-testcases/tls13-kex-modes.sh
@@ -882,6 +882,81 @@ run_test    "TLS 1.3: G->m: psk_or_ephemeral/psk_or_ephemeral, fail, key materia
             -S "key exchange mode: psk_ephemeral"  \
             -S "key exchange mode: ephemeral"
 
+requires_gnutls_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: G->m: psk_ephemeral group(secp256r1) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3:-GROUP-ALL:+GROUP-SECP256R1 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            0 \
+            -s "write selected_group: secp256r1" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
+requires_gnutls_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: G->m: psk_ephemeral group(secp384r1) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3:-GROUP-ALL:+GROUP-SECP384R1 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            0 \
+            -s "write selected_group: secp384r1" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
+requires_gnutls_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: G->m: psk_ephemeral group(secp521r1) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3:-GROUP-ALL:+GROUP-SECP521R1 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            0 \
+            -s "write selected_group: secp521r1" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
+requires_gnutls_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: G->m: psk_ephemeral group(x25519) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3:-GROUP-ALL:+GROUP-X25519 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            0 \
+            -s "write selected_group: x25519" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
+requires_gnutls_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: G->m: psk_ephemeral group(x448) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3:-GROUP-ALL:+GROUP-X448 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            0 \
+            -s "write selected_group: x448" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
 requires_openssl_tls1_3
 requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
 requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
@@ -1445,3 +1520,73 @@ run_test    "TLS 1.3: O->m: all/psk_or_ephemeral, fail, key material mismatch" \
             -S "key exchange mode: psk$"  \
             -S "key exchange mode: psk_ephemeral"  \
             -S "key exchange mode: ephemeral"
+
+requires_openssl_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: O->m: psk_ephemeral group(secp256r1) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$O_NEXT_CLI -tls1_3 -msg  -allow_no_dhe_kex -groups P-256 \
+                         -psk_identity Client_identity  -psk 6162636465666768696a6b6c6d6e6f70" \
+            0 \
+            -s "write selected_group: secp256r1" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
+requires_openssl_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: O->m: psk_ephemeral group(secp384r1) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$O_NEXT_CLI -tls1_3 -msg  -allow_no_dhe_kex -groups secp384r1 \
+                         -psk_identity Client_identity  -psk 6162636465666768696a6b6c6d6e6f70" \
+            0 \
+            -s "write selected_group: secp384r1" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
+requires_openssl_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: O->m: psk_ephemeral group(secp521r1) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$O_NEXT_CLI -tls1_3 -msg  -allow_no_dhe_kex -groups secp521r1 \
+                         -psk_identity Client_identity  -psk 6162636465666768696a6b6c6d6e6f70" \
+            0 \
+            -s "write selected_group: secp521r1" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
+requires_openssl_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: O->m: psk_ephemeral group(x25519) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$O_NEXT_CLI -tls1_3 -msg  -allow_no_dhe_kex -groups X25519 \
+                         -psk_identity Client_identity  -psk 6162636465666768696a6b6c6d6e6f70" \
+            0 \
+            -s "write selected_group: x25519" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
+requires_openssl_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test    "TLS 1.3: O->m: psk_ephemeral group(x448) check, good" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70" \
+            "$O_NEXT_CLI -tls1_3 -msg  -allow_no_dhe_kex -groups X448 \
+                         -psk_identity Client_identity  -psk 6162636465666768696a6b6c6d6e6f70" \
+            0 \
+            -s "write selected_group: x448" \
+            -S "key exchange mode: psk$"  \
+            -s "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"