diff --git a/phpseclib/File/ASN1.php b/phpseclib/File/ASN1.php
index 8a7286b1..3b8f11bd 100644
--- a/phpseclib/File/ASN1.php
+++ b/phpseclib/File/ASN1.php
@@ -850,7 +850,7 @@ class ASN1
                     if ($mapping['type'] == self::TYPE_SET) {
                         sort($value);
                     }
-                    $value = implode($value, '');
+                    $value = implode('', $value);
                     break;
                 }