diff --git a/phpseclib/File/ASN1.php b/phpseclib/File/ASN1.php
index 1a79173d..4bd355a1 100644
--- a/phpseclib/File/ASN1.php
+++ b/phpseclib/File/ASN1.php
@@ -947,7 +947,7 @@ class File_ASN1
                     if ($mapping['type'] == FILE_ASN1_TYPE_SET) {
                         sort($value);
                     }
-                    $value = implode($value, '');
+                    $value = implode('', $value);
                     break;
                 }