diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4f500ae3..e1505c32 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,6 +26,7 @@ jobs:
           - '8.1'
           - '8.2'
           - '8.3'
+          - '8.4'
 
     steps:
       - name: Checkout
@@ -176,6 +177,7 @@ jobs:
           - '8.1'
           - '8.2'
           - '8.3'
+          - '8.4'
         dependencies:
           - lowest
           - highest
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9d9e05ba..15618086 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 ## x.y.z
 
 ### Added
+- Add support for PHP 8.4 (#1278)
 - Support `:root` pseudo-class (#1306)
 - Add CSS selectors exclusion feature (#1236)
 
diff --git a/composer.json b/composer.json
index 66d3c86a..5bee683f 100644
--- a/composer.json
+++ b/composer.json
@@ -37,7 +37,7 @@
         "source": "https://github.com/MyIntervals/emogrifier"
     },
     "require": {
-        "php": "~7.3.0 || ~7.4.0 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0",
+        "php": "~7.3.0 || ~7.4.0 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0 || ~8.4.0",
         "ext-dom": "*",
         "ext-libxml": "*",
         "sabberworm/php-css-parser": "v8.x-dev",