diff --git a/testssl.sh b/testssl.sh
index 173943c..acb6c05 100755
--- a/testssl.sh
+++ b/testssl.sh
@@ -10239,6 +10239,7 @@ run_fs() {
      local -a supported_curve
      local -i nr_supported_ciphers=0 nr_curves=0 nr_ossl_curves=0 i j low high
      local fs_ciphers curves_offered="" curves_to_test temp
+     local curves_option="" curves_list1="" curves_list2=""
      local len1 len2 curve_found
      local key_bitstring quality_str
      local -i len_dh_p quality
@@ -10307,6 +10308,12 @@ run_fs() {
           tls_sockets "04" "${fs_hex_cipher_list:2}, 00,ff"
           sclient_success=$?
           [[ $sclient_success -eq 2 ]] && sclient_success=0
+          # Sometimes a TLS 1.3 ClientHello will fail, but a TLS 1.2 ClientHello will succeed. See #2131.
+          if [[ $sclient_success -ne 0 ]]; then
+               tls_sockets "03" "${fs_hex_cipher_list:2}, 00,ff"
+               sclient_success=$?
+               [[ $sclient_success -eq 2 ]] && sclient_success=0
+          fi
      else
           debugme echo $nr_supported_ciphers
           debugme echo $(actually_supported_osslciphers $fs_cipher_list "ALL")
@@ -10320,6 +10327,38 @@ run_fs() {
           sclient_connect_successful $? $TMPFILE
           sclient_success=$?
           [[ $sclient_success -eq 0 ]] && [[ $(grep -ac "BEGIN CERTIFICATE" $TMPFILE) -eq 0 ]] && sclient_success=1
+          # Sometimes a TLS 1.3 ClientHello will fail, but a TLS 1.2 ClientHello will succeed. See #2131.
+          if [[ $sclient_success -ne 0 ]] && "$HAS_TLS13"; then
+               # By default, OpenSSL 1.1.1 and above only include a few curves in the ClientHello, so in order
+               # to test all curves, the -curves option must be added. In addition, OpenSSL limits the number of
+               # curves that can be specified to 28. So, if more than 28 curves are supported, then the curves must
+               # be tested in batches.
+               if [[ "$(count_words "$OSSL_SUPPORTED_CURVES")" -le 28 ]]; then
+                    curves_list1="$(strip_trailing_space "$(strip_leading_space "$OSSL_SUPPORTED_CURVES")")"
+                    curves_list1="${curves_list1// /:}"
+               else
+                    # Place the first 28 supported curves in curves_list1 and the remainder in curves_list2.
+                    curves_list1="$(strip_trailing_space "$(strip_leading_space "$OSSL_SUPPORTED_CURVES")")"
+                    curves_list1="${curves_list1//  / }"
+                    curves_list2="${curves_list1#* * * * * * * * * * * * * * * * * * * * * * * * * * * * }"
+                    curves_list1="${curves_list1%$curves_list2}"
+                    curves_list1="$(strip_trailing_space "$curves_list1")"
+                    curves_list1="${curves_list1// /:}"
+                    curves_list2="${curves_list2// /:}"
+               fi
+               curves_option="-curves $curves_list1"
+               $OPENSSL s_client $(s_client_options "-cipher $fs_cipher_list $curves_option $STARTTLS $BUGS -connect $NODEIP:$PORT $PROXY $SNI") >$TMPFILE 2>$ERRFILE </dev/null
+               sclient_connect_successful $? $TMPFILE
+               sclient_success=$?
+               [[ $sclient_success -eq 0 ]] && [[ $(grep -ac "BEGIN CERTIFICATE" $TMPFILE) -eq 0 ]] && sclient_success=1
+               if [[ $sclient_success -ne 0 ]] && [[ -n "$curves_list2" ]]; then
+                    curves_option="-curves $curves_list2"
+                    $OPENSSL s_client $(s_client_options "-cipher $fs_cipher_list $curves_option $STARTTLS $BUGS -connect $NODEIP:$PORT $PROXY $SNI") >$TMPFILE 2>$ERRFILE </dev/null
+                    sclient_connect_successful $? $TMPFILE
+                    sclient_success=$?
+                    [[ $sclient_success -eq 0 ]] && [[ $(grep -ac "BEGIN CERTIFICATE" $TMPFILE) -eq 0 ]] && sclient_success=1
+               fi
+          fi
      fi
 
      if [[ $sclient_success -ne 0 ]]; then
@@ -10359,7 +10398,7 @@ run_fs() {
                          fi
                     done
                     [[ -z "$ciphers_to_test" ]] && [[ -z "$tls13_ciphers_to_test" ]] && break
-                    $OPENSSL s_client $(s_client_options "$proto -cipher "\'${ciphers_to_test:1}\'" -ciphersuites "\'${tls13_ciphers_to_test:1}\'" $STARTTLS $BUGS -connect $NODEIP:$PORT $PROXY $SNI") &>$TMPFILE </dev/null
+                    $OPENSSL s_client $(s_client_options "$proto -cipher "\'${ciphers_to_test:1}\'" -ciphersuites "\'${tls13_ciphers_to_test:1}\'" $curves_option $STARTTLS $BUGS -connect $NODEIP:$PORT $PROXY $SNI") &>$TMPFILE </dev/null
                     sclient_connect_successful $? $TMPFILE || break
                     fs_cipher=$(get_cipher $TMPFILE)
                     [[ -z "$fs_cipher" ]] && break