diff --git a/CHANGELOG.md b/CHANGELOG.md
index cf731b3..b27b969 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,18 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 
+## v2.3.1 - 2024.08.19
+
+### Fixed
+
+- Fix facets applying on non-main queries ([#49](https://github.com/studiometa/wp-toolkit/issues/49), [#50](https://github.com/studiometa/wp-toolkit/pull/50), [9c098c7](https://github.com/studiometa/wp-toolkit/commit/9c098c7))
+
+### Added
+
+- Add a CLAUDE.md file ([c28b253](https://github.com/studiometa/wp-toolkit/commit/c28b253))
+
+## v2.3.0 - 2024.08.14
+
 ### Added
 
 - Add support for custom taxonomies filtering ([#42](https://github.com/studiometa/wp-toolkit/issues/42), [#43](https://github.com/studiometa/wp-toolkit/pull/43), [ae541b5](https://github.com/studiometa/wp-toolkit/commit/ae541b5))
diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 0000000..7f2b2ea
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,14 @@
+# WordPress Toolkit by Studio Meta
+
+## Development commands
+
+- `ddev start` to start the DDEV project where the PHPUnit tests will be run
+- `ddev exec composer test` to run the PHPUnit tests
+- `composer lint:style` to check for code quality with PHPCS
+- `composer fix:style` to fix fixable errors reported by PHPCS
+- `composer lint:static` to do static analysis with PHPStan
+
+## Guidelines
+
+- Follow existing patterns
+- Follow modern PHP features and standard 
diff --git a/src/Managers/FacetsManager.php b/src/Managers/FacetsManager.php
index 5dc74d7..dc778bb 100644
--- a/src/Managers/FacetsManager.php
+++ b/src/Managers/FacetsManager.php
@@ -58,7 +58,7 @@ public function run()
      */
     public function add_facets_to_query(WP_Query &$query): void
     {
-        if (!is_array($this->facets)) {
+        if (!is_array($this->facets) || !$query->is_main_query()) {
             return;
         }
 
diff --git a/tests/Managers/FacetsManagerTest.php b/tests/Managers/FacetsManagerTest.php
index 25e6236..72603ac 100644
--- a/tests/Managers/FacetsManagerTest.php
+++ b/tests/Managers/FacetsManagerTest.php
@@ -210,4 +210,21 @@ public function test_it_should_handle_array_values_in_facets()
         $this->assertEquals(['slug1', 'slug2'], $tax_query[0]['terms']);
         $this->assertEquals('slug', $tax_query[0]['field']);
     }
+
+    public function test_it_should_not_add_facets_to_non_main_query()
+    {
+        request()->query->set('facets', ['cat' => 1]);
+        $manager = new FacetsManager();
+        $manager->run();
+
+        // Create a non-main query
+        $secondary_query = new WP_Query();
+        $secondary_query->init();
+        
+        // Manually call the method to simulate what happens on pre_get_posts
+        $manager->add_facets_to_query($secondary_query);
+
+        // The facets should not be applied to the secondary query
+        $this->assertFalse(isset($secondary_query->query_vars['cat']));
+    }
 }