diff --git a/acme.sh b/acme.sh
index db77c22..1bd955b 100755
--- a/acme.sh
+++ b/acme.sh
@@ -1088,7 +1088,7 @@ _readKeyLengthFromCSR() {
     echo "$_outcsr" | _egrep_o "^ *ASN1 OID:.*" | cut -d ':' -f 2 | tr -d ' '
   else
     _debug "RSA CSR"
-    echo "$_outcsr" | _egrep_o "^ *Public.Key:.*" | cut -d '(' -f 2 | cut -d ' ' -f 1
+    echo "$_outcsr" | _egrep_o "(^ *|^RSA )Public.Key:.*" | cut -d '(' -f 2 | cut -d ' ' -f 1
   fi
 }