diff --git a/.gitattributes b/.gitattributes
index 7d92ee940d..f7fa86e5fc 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -7,7 +7,6 @@
 /gulp-tasks export-ignore
 /lang export-ignore
 /tests export-ignore
-/vendor/ export-ignore
 /node_modules export-ignore
 
 /.babelrc export-ignore
diff --git a/.github/workflows/build-and-tag.yml b/.github/workflows/build-and-tag.yml
index 397993c837..2587b42195 100644
--- a/.github/workflows/build-and-tag.yml
+++ b/.github/workflows/build-and-tag.yml
@@ -12,6 +12,15 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v3
 
+    - name: Set PHP version
+      uses: shivammathur/setup-php@v2
+      with:
+        php-version: '7.0' # Minimum required version
+        coverage: none
+
+    - name: composer install
+      run: composer install --no-dev -o
+
     - name: install node v18
       uses: actions/setup-node@v3
       with:
diff --git a/composer.json b/composer.json
index fa7c47e825..4cdd8fb141 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,8 @@
   ],
   "require": {
     "php": ">=7.0",
-    "composer/installers": "^1.0 || ^2.0"
+    "composer/installers": "^1.0 || ^2.0",
+    "psr/container": "^1.0 || ^2.0"
   },
   "require-dev": {
     "10up/phpcs-composer": "dev-master",
diff --git a/composer.lock b/composer.lock
index 369da8a481..e11d5f07c2 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": "ff870c75078541fd7f71487b281ddd46",
+    "content-hash": "cdb2b0fa9e6fcd5faa3d1cde9e40827b",
     "packages": [
         {
             "name": "composer/installers",
@@ -150,6 +150,59 @@
                 }
             ],
             "time": "2022-08-20T06:45:11+00:00"
+        },
+        {
+            "name": "psr/container",
+            "version": "2.0.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/php-fig/container.git",
+                "reference": "c71ecc56dfe541dbd90c5360474fbc405f8d5963"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/php-fig/container/zipball/c71ecc56dfe541dbd90c5360474fbc405f8d5963",
+                "reference": "c71ecc56dfe541dbd90c5360474fbc405f8d5963",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=7.4.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "2.0.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Psr\\Container\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "PHP-FIG",
+                    "homepage": "https://www.php-fig.org/"
+                }
+            ],
+            "description": "Common Container Interface (PHP FIG PSR-11)",
+            "homepage": "https://github.com/php-fig/container",
+            "keywords": [
+                "PSR-11",
+                "container",
+                "container-interface",
+                "container-interop",
+                "psr"
+            ],
+            "support": {
+                "issues": "https://github.com/php-fig/container/issues",
+                "source": "https://github.com/php-fig/container/tree/2.0.2"
+            },
+            "time": "2021-11-05T16:47:00+00:00"
         }
     ],
     "packages-dev": [
diff --git a/elasticpress.php b/elasticpress.php
index 8ea0af3380..9a3bd39874 100644
--- a/elasticpress.php
+++ b/elasticpress.php
@@ -29,6 +29,11 @@
 	exit; // Exit if accessed directly.
 }
 
+// Require Composer autoloader if it exists.
+if ( file_exists( __DIR__ . '/vendor/autoload.php' ) ) {
+	require_once __DIR__ . '/vendor/autoload.php';
+}
+
 define( 'EP_URL', plugin_dir_url( __FILE__ ) );
 define( 'EP_PATH', plugin_dir_path( __FILE__ ) );
 define( 'EP_FILE', plugin_basename( __FILE__ ) );
diff --git a/includes/classes/Container.php b/includes/classes/Container.php
index 8bb34b7b55..b324d95ca4 100644
--- a/includes/classes/Container.php
+++ b/includes/classes/Container.php
@@ -9,12 +9,13 @@
 
 namespace ElasticPress;
 
+use \Psr\Container\ContainerInterface;
+use \Psr\Container\NotFoundExceptionInterface;
+
 /**
- * (semi-)PSR11 compliant container class
- *
- * Although type hinting will work, we do not implement the interfaces yet.
+ * PSR11 compliant container class
  */
-final class Container {
+final class Container implements ContainerInterface {
 	/**
 	 * Hold all instances
 	 *
@@ -27,13 +28,13 @@ final class Container {
 	 *
 	 * @param string $id Identifier of the entry to look for.
 	 *
-	 * @throws \Exception No entry was found for **this** identifier.
+	 * @throws NotFoundExceptionInterface No entry was found for **this** identifier.
 	 *
 	 * @return mixed Entry.
 	 */
 	public function get( string $id ) {
 		if ( ! isset( $this->instances[ $id ] ) ) {
-			throw new \Exception( 'Class not found' );
+			throw new NotFoundExceptionInterface( 'Class not found' );
 		}
 
 		return $this->instances[ $id ];