diff --git a/composer.json b/composer.json
index a3f29c8..f12f21e 100644
--- a/composer.json
+++ b/composer.json
@@ -31,7 +31,9 @@
         "web-token/jwt-signature-algorithm-rsa": "^2.0",
         "web-token/jwt-core": "^2.0",
         "psr/simple-cache": "^1.0",
-        "psr/http-factory": "^1.0"
+        "psr/http-factory": "^1.0",
+        "ext-json": "*",
+        "ext-gmp": "*"
     },
     "require-dev": {
         "php-http/message": "^1.8",