diff --git a/acme.sh b/acme.sh
index 9ff8001..1ddec82 100755
--- a/acme.sh
+++ b/acme.sh
@@ -1136,7 +1136,7 @@ _readKeyLengthFromCSR() {
     echo "$_outcsr" | tr "\t" " " | _egrep_o "^ *ASN1 OID:.*" | cut -d ':' -f 2 | tr -d ' '
   else
     _debug "RSA CSR"
-    echo "$_outcsr" | tr "\t" " " | _egrep_o "(^ *|RSA )Public.Key:.*" | cut -d '(' -f 2 | cut -d ' ' -f 1
+    echo "$_outcsr" | tr "\t" " " | (_egrep_o "^ *Public.Key:.*" || _egrep_o "RSA Public.Key:.*") | cut -d '(' -f 2 | cut -d ' ' -f 1
   fi
 }