diff --git a/acme.sh b/acme.sh
index a9301e10..2cb9dd00 100755
--- a/acme.sh
+++ b/acme.sh
@@ -1122,9 +1122,14 @@ _createkey() {
     fi
   fi
 
+  __traditional=""
+  if _contains "$(${ACME_OPENSSL_BIN:-openssl} help genrsa 2>&1)" "-traditional"; then
+    __traditional="-traditional"
+  fi
+
   if _isEccKey "$length"; then
     _debug "Using ec name: $eccname"
-    if _opkey="$(${ACME_OPENSSL_BIN:-openssl} ecparam -name "$eccname" -genkey 2>/dev/null)"; then
+    if _opkey="$(${ACME_OPENSSL_BIN:-openssl} ecparam $__traditional -name "$eccname" -genkey 2>/dev/null)"; then
       echo "$_opkey" >"$f"
     else
       _err "error ecc key name: $eccname"
@@ -1132,7 +1137,7 @@ _createkey() {
     fi
   else
     _debug "Using RSA: $length"
-    if _opkey="$(${ACME_OPENSSL_BIN:-openssl} genrsa "$length" 2>/dev/null)"; then
+    if _opkey="$(${ACME_OPENSSL_BIN:-openssl} genrsa $__traditional "$length" 2>/dev/null)"; then
       echo "$_opkey" >"$f"
     else
       _err "error rsa key: $length"