diff --git a/composer.json b/composer.json
index aa48e52..b0031c7 100644
--- a/composer.json
+++ b/composer.json
@@ -30,7 +30,7 @@
 		}
 	},
 	"require": {
-		"php" : ">=7.0.0",
+		"php" : ">=7.1.0",
 		"kartenmacherei/kam-newrelic": "^1.0"
 	},
 	"require-dev": {
diff --git a/composer.lock b/composer.lock
index 8a6202b..5730968 100644
--- a/composer.lock
+++ b/composer.lock
@@ -1,10 +1,10 @@
 {
     "_readme": [
         "This file locks the dependencies of your project to a known state",
-        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "0003599887e52aa1bfc0fa428b68cde6",
+    "content-hash": "9c22491b117340fd4cd9d4c8e653583a",
     "packages": [
         {
             "name": "kartenmacherei/kam-newrelic",
@@ -1519,7 +1519,8 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": ">=7.0.0"
+        "php": ">=7.1.0"
     },
-    "platform-dev": []
+    "platform-dev": [],
+    "plugin-api-version": "2.6.0"
 }
diff --git a/src/JsonArray.php b/src/JsonArray.php
index b448627..163d13f 100644
--- a/src/JsonArray.php
+++ b/src/JsonArray.php
@@ -16,7 +16,7 @@ public function __construct(array $data)
         $this->data = $data;
     }
 
-    public function current()
+    public function current(): mixed
     {
         $current = current($this->data);
         if (is_array($current)) {
@@ -28,12 +28,12 @@ public function current()
         return $current;
     }
 
-    public function next()
+    public function next(): void
     {
         next($this->data);
     }
 
-    public function key()
+    public function key(): mixed
     {
         return key($this->data);
     }
@@ -46,7 +46,7 @@ public function valid():bool
         return array_key_exists($this->key(), $this->data);
     }
 
-    public function rewind()
+    public function rewind(): void
     {
         reset($this->data);
     }