diff --git a/.forgejo/workflows/phpunit.yml b/.forgejo/workflows/phpunit.yml
index a893dce..3e6d9f7 100644
--- a/.forgejo/workflows/phpunit.yml
+++ b/.forgejo/workflows/phpunit.yml
@@ -21,7 +21,7 @@ jobs:
           MYSQL_ROOT_PASSWORD: root
     strategy:
       matrix:
-        php-version: ['8.1', '8.2', '8.3']
+        php-version: ['7.4', '8.0', '8.1', '8.2', '8.3']
     name: PHPUnit – PHP ${{ matrix.php-version }}
     env:
       extensions: mysql
@@ -45,7 +45,7 @@ jobs:
         with:
           path: |
             ./vendor/
-          key: cache-composer-phpunit-1
+          key: cache-composer-phpunit-2
 
       - name: Setup PHP
         uses: https://github.com/shivammathur/setup-php@v2
diff --git a/README.md b/README.md
index e0f27c8..2a8553d 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 **Requires at least:** 6.5  
 **Tested up to:** 6.6  
 **Stable tag:** 0.2.0  
-**Requires PHP:** 8.1  
+**Requires PHP:** 7.4  
 **License:** AGPL-3.0-or-later  
 **License URI:** https://www.gnu.org/licenses/agpl-3.0.html  
 Integrating popular event plugins with the ActivityPub plugin.
diff --git a/activitypub-event-bridge.php b/activitypub-event-bridge.php
index 41557c8..4278457 100644
--- a/activitypub-event-bridge.php
+++ b/activitypub-event-bridge.php
@@ -9,7 +9,7 @@
  * Text Domain:  activitypub-event-bridge
  * License:      AGPL-3.0-or-later
  * License URI:  https://www.gnu.org/licenses/agpl-3.0.html
- * Requires PHP: 8.1
+ * Requires PHP: 7.4
  *
  * Requires at least ActivityPub plugin with version >= 3.2.2. ActivityPub plugin tested up to: 4.0.1.
  *
diff --git a/composer.json b/composer.json
index 6236dfc..4da8b48 100644
--- a/composer.json
+++ b/composer.json
@@ -4,7 +4,7 @@
     "description": "The ActivityPub Event Bridge help for event custom post types to federate properly.",
     "type": "wordpress-plugin",
     "require": {
-        "php": ">=8.1.0",
+        "php": ">=7.4.0",
         "composer/installers": "^2.0"
     },
     "require-dev": {
diff --git a/includes/activitypub/transformer/class-the-events-calendar.php b/includes/activitypub/transformer/class-the-events-calendar.php
index 2fe7274..f50fa29 100644
--- a/includes/activitypub/transformer/class-the-events-calendar.php
+++ b/includes/activitypub/transformer/class-the-events-calendar.php
@@ -121,9 +121,9 @@ final class The_Events_Calendar extends Event {
 	/**
 	 * Get the event location.
 	 *
-	 * @return Place|array The place/venue if one is set.
+	 * @return ?Place The place/venue if one is set.
 	 */
-	public function get_location(): Place|null {
+	public function get_location(): ?Place {
 		// Get short handle for the venues.
 		$venues = $this->tribe_event->venues;
 
diff --git a/includes/class-setup.php b/includes/class-setup.php
index 966d1d3..2912002 100644
--- a/includes/class-setup.php
+++ b/includes/class-setup.php
@@ -252,7 +252,7 @@ class Setup {
 	 *
 	 * @return \Activitypub\Transformer\Base|null
 	 */
-	public function register_activitypub_event_transformer( $transformer, $wp_object, $object_class ): \Activitypub\Transformer\Base|null {
+	public function register_activitypub_event_transformer( $transformer, $wp_object, $object_class ): \Activitypub\Transformer\Base {
 		// If the current WordPress object is not a post (e.g., a WP_Comment), don't change the transformer.
 		if ( 'WP_Post' !== $object_class ) {
 			return $transformer;
diff --git a/readme.txt b/readme.txt
index 29f5479..df031ea 100644
--- a/readme.txt
+++ b/readme.txt
@@ -4,7 +4,7 @@ Tags: events, fediverse, activitypub, calendar
 Requires at least: 6.5
 Tested up to: 6.6
 Stable tag: 0.2.0
-Requires PHP: 8.1
+Requires PHP: 7.4
 License: AGPL-3.0-or-later
 License URI: https://www.gnu.org/licenses/agpl-3.0.html
 Integrating popular event plugins with the ActivityPub plugin.