diff --git a/composer.json b/composer.json
index 4187bb3..61072d9 100644
--- a/composer.json
+++ b/composer.json
@@ -22,7 +22,7 @@
     "php": ">=8.0",
     "guzzlehttp/guzzle": ">=6.3.3",
     "psr/log": ">=1",
-    "psr/simple-cache": "1.*|2.*",
+    "psr/simple-cache": "1.*|2.*|3.*",
     "ext-json": "*"
   },
   "require-dev": {
diff --git a/src/Cache/MemoryCache.php b/src/Cache/MemoryCache.php
index 8be88b7..9386a5b 100644
--- a/src/Cache/MemoryCache.php
+++ b/src/Cache/MemoryCache.php
@@ -27,7 +27,7 @@ public static function getInstance(): MemoryCache
     /**
      * @inheritDoc
      */
-    public function get($key, $default = null)
+    public function get($key, $default = null): mixed
     {
         return $this->cache[$key] ?? $default;
     }
@@ -38,7 +38,7 @@ public function get($key, $default = null)
      * @param $ttl - Ignored since its in memory
      * @return bool|void
      */
-    public function set($key, $value, $ttl = null)
+    public function set($key, $value, $ttl = null): bool
     {
         $this->cache[$key] = $value;
         return true;
@@ -47,7 +47,7 @@ public function set($key, $value, $ttl = null)
     /**
      * @inheritDoc
      */
-    public function delete($key)
+    public function delete($key): bool
     {
         $return = false;
         if ($this->has($key)) {
@@ -61,7 +61,7 @@ public function delete($key)
     /**
      * @inheritDoc
      */
-    public function clear()
+    public function clear(): bool
     {
         $this->cache = [];
         return true;
@@ -70,7 +70,7 @@ public function clear()
     /**
      * @inheritDoc
      */
-    public function getMultiple($keys, $default = null)
+    public function getMultiple($keys, $default = null): iterable
     {
         $items = $default ?? [];
         foreach ($keys as $key) {
@@ -89,7 +89,7 @@ public function getMultiple($keys, $default = null)
     /**
      * @inheritDoc
      */
-    public function setMultiple($values, $ttl = null)
+    public function setMultiple($values, $ttl = null): bool
     {
         foreach ($values as $key => $value) {
             $this->set($key, $value, $ttl);
@@ -101,7 +101,7 @@ public function setMultiple($values, $ttl = null)
     /**
      * @inheritDoc
      */
-    public function deleteMultiple($keys)
+    public function deleteMultiple($keys): bool
     {
         $return = true;
         foreach ($keys as $key) {
@@ -116,7 +116,7 @@ public function deleteMultiple($keys)
     /**
      * @inheritDoc
      */
-    public function has($key)
+    public function has($key): bool
     {
         return isset($this->cache[$key]);
     }
diff --git a/src/Endpoint/Traits/JsonHandlerTrait.php b/src/Endpoint/Traits/JsonHandlerTrait.php
index 3422db2..c1c8e6b 100644
--- a/src/Endpoint/Traits/JsonHandlerTrait.php
+++ b/src/Endpoint/Traits/JsonHandlerTrait.php
@@ -19,7 +19,7 @@ protected function configureJsonRequest(Request $request): Request
      */
     public function getResponseContent(Response $response, bool $associative = true): mixed
     {
-        if (!$this->_respContent) {
+        if (empty($this->_respContent)) {
             $this->_respContent = $response->getBody()->getContents();
             $response->getBody()->rewind();
         }