diff --git a/composer.json b/composer.json
index 003eac5..ea7a0bd 100644
--- a/composer.json
+++ b/composer.json
@@ -19,7 +19,7 @@
     "homepage": "http://www.php-cache.com/en/latest/",
     "require": {
         "php": ">=7.4",
-        "psr/cache": "^1.0 || ^2.0",
+        "psr/cache": "^1.0 || ^2.0 || ^3.0",
         "psr/simple-cache": "^1.0"
     },
     "require-dev": {
@@ -35,11 +35,13 @@
     "prefer-stable": true,
     "autoload": {
         "psr-4": {
-            "Cache\\Bridge\\SimpleCache\\": ""
-        },
-        "exclude-from-classmap": [
-            "/Tests/"
-        ]
+            "Cache\\Bridge\\SimpleCache\\": "src"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "Cache\\Bridge\\SimpleCache\\Tests\\": "tests"
+        }
     },
     "extra": {
         "branch-alias": {
diff --git a/Exception/CacheException.php b/src/Exception/CacheException.php
similarity index 100%
rename from Exception/CacheException.php
rename to src/Exception/CacheException.php
diff --git a/Exception/InvalidArgumentException.php b/src/Exception/InvalidArgumentException.php
similarity index 100%
rename from Exception/InvalidArgumentException.php
rename to src/Exception/InvalidArgumentException.php
diff --git a/SimpleCacheBridge.php b/src/SimpleCacheBridge.php
similarity index 91%
rename from SimpleCacheBridge.php
rename to src/SimpleCacheBridge.php
index a0047be..f00cde4 100644
--- a/SimpleCacheBridge.php
+++ b/src/SimpleCacheBridge.php
@@ -40,7 +40,7 @@ public function __construct(CacheItemPoolInterface $cacheItemPool)
     /**
      * {@inheritdoc}
      */
-    public function get($key, $default = null)
+    public function get($key, mixed $default = null): mixed
     {
         try {
             $item = $this->cacheItemPool->getItem($key);
@@ -58,7 +58,7 @@ public function get($key, $default = null)
     /**
      * {@inheritdoc}
      */
-    public function set($key, $value, $ttl = null)
+    public function set($key, mixed $value, null|int|\DateInterval $ttl = null): bool
     {
         try {
             $item = $this->cacheItemPool->getItem($key);
@@ -75,7 +75,7 @@ public function set($key, $value, $ttl = null)
     /**
      * {@inheritdoc}
      */
-    public function delete($key)
+    public function delete(string $key): bool
     {
         try {
             return $this->cacheItemPool->deleteItem($key);
@@ -87,7 +87,7 @@ public function delete($key)
     /**
      * {@inheritdoc}
      */
-    public function clear()
+    public function clear(): bool
     {
         return $this->cacheItemPool->clear();
     }
@@ -95,7 +95,7 @@ public function clear()
     /**
      * {@inheritdoc}
      */
-    public function getMultiple($keys, $default = null)
+    public function getMultiple(iterable $keys, mixed $default = null): iterable
     {
         if (!is_array($keys)) {
             if (!$keys instanceof \Traversable) {
@@ -122,7 +122,7 @@ public function getMultiple($keys, $default = null)
      *
      * @return \Generator
      */
-    private function generateValues($default, $items)
+    private function generateValues(mixed $default, $items)
     {
         foreach ($items as $key => $item) {
             /** @type $item CacheItemInterface */
@@ -137,7 +137,7 @@ private function generateValues($default, $items)
     /**
      * {@inheritdoc}
      */
-    public function setMultiple($values, $ttl = null)
+    public function setMultiple(iterable $values, null|int|\DateInterval $ttl = null): bool
     {
         if (!is_array($values)) {
             if (!$values instanceof \Traversable) {
@@ -191,7 +191,7 @@ public function setMultiple($values, $ttl = null)
     /**
      * {@inheritdoc}
      */
-    public function deleteMultiple($keys)
+    public function deleteMultiple(iterable $keys): bool
     {
         if (!is_array($keys)) {
             if (!$keys instanceof \Traversable) {
@@ -213,7 +213,7 @@ public function deleteMultiple($keys)
     /**
      * {@inheritdoc}
      */
-    public function has($key)
+    public function has(string $key): bool
     {
         try {
             return $this->cacheItemPool->hasItem($key);