diff --git a/composer.json b/composer.json
index cdb6050..e565f10 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
     ],
     "require": {
         "php": ">=5.6.0",
-        "phpseclib/phpseclib": "3.0.20"
+        "phpseclib/phpseclib": "~3.0.20"
     },
     "require-dev": {
         "phpunit/phpunit": "3.7.*"