diff --git a/composer.json b/composer.json
index 3ca798e..6c5fc60 100644
--- a/composer.json
+++ b/composer.json
@@ -22,7 +22,7 @@
     },
     "require": {
         "php": ">=5.3.3",
-        "phpseclib/phpseclib": ">=2.0.36 <3.0.0"
+        "phpseclib/phpseclib": ">=2.0.47 <3.0.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.8.35|^5.7|^6.0|^9.4"