diff --git a/composer.json b/composer.json
index aca927c..c73f43b 100644
--- a/composer.json
+++ b/composer.json
@@ -5,6 +5,7 @@
         "php": "^7.1.3",
         "ext-ctype": "*",
         "ext-iconv": "*",
+        "ext-json": "^1.5",
         "guzzlehttp/guzzle": "^6.3",
         "josephlavin/tap": "^1.0",
         "symfony/cache": "4.2.*",
diff --git a/composer.lock b/composer.lock
index 4340eea..800cf9c 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "35f8b30095e57576a83ae4bdaa898a19",
+    "content-hash": "ccd0911d9e64d0a7e474b2f57a50a49a",
     "packages": [
         {
             "name": "guzzlehttp/guzzle",
@@ -2517,7 +2517,8 @@
     "platform": {
         "php": "^7.1.3",
         "ext-ctype": "*",
-        "ext-iconv": "*"
+        "ext-iconv": "*",
+        "ext-json": "^1.5"
     },
     "platform-dev": []
 }