diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e59e02a2..68cc62bf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -46,6 +46,7 @@ jobs:
           - "8.1"
           - "8.2"
           - "8.3"
+          - "8.4"
   code-quality:
     name: "Code quality checks"
     runs-on: ubuntu-24.04
@@ -189,6 +190,12 @@ jobs:
           - typo3-version: "^11.5"
             php-version: "8.3"
             composer-dependencies: highest
+          - typo3-version: "^11.5"
+            php-version: "8.4"
+            composer-dependencies: lowest
+          - typo3-version: "^11.5"
+            php-version: "8.4"
+            composer-dependencies: highest
           - typo3-version: "^12.4"
             php-version: "8.1"
             composer-dependencies: lowest
@@ -207,6 +214,12 @@ jobs:
           - typo3-version: "^12.4"
             php-version: "8.3"
             composer-dependencies: highest
+          - typo3-version: "^12.4"
+            php-version: "8.4"
+            composer-dependencies: lowest
+          - typo3-version: "^12.4"
+            php-version: "8.4"
+            composer-dependencies: highest
   functional-tests:
     name: "Functional tests"
     runs-on: ubuntu-24.04
@@ -296,6 +309,12 @@ jobs:
           - typo3-version: "^11.5"
             php-version: "8.3"
             composer-dependencies: highest
+          - typo3-version: "^11.5"
+            php-version: "8.4"
+            composer-dependencies: lowest
+          - typo3-version: "^11.5"
+            php-version: "8.4"
+            composer-dependencies: highest
           - typo3-version: "^12.4"
             php-version: "8.1"
             composer-dependencies: lowest
@@ -314,6 +333,12 @@ jobs:
           - typo3-version: "^12.4"
             php-version: "8.3"
             composer-dependencies: highest
+          - typo3-version: "^12.4"
+            php-version: "8.4"
+            composer-dependencies: lowest
+          - typo3-version: "^12.4"
+            php-version: "8.4"
+            composer-dependencies: highest
   shellcheck:
     name: Check shell scripts
     runs-on: ubuntu-24.04
diff --git a/.gitlab/pipeline/jobs/php-lint-php8.4.yml b/.gitlab/pipeline/jobs/php-lint-php8.4.yml
new file mode 100644
index 00000000..40718ff0
--- /dev/null
+++ b/.gitlab/pipeline/jobs/php-lint-php8.4.yml
@@ -0,0 +1,7 @@
+php-lint-php8.3:
+  extends: .composer-update
+  image: ghcr.io/typo3/core-testing-php84:latest
+  stage: lint
+  needs: [ ]
+  script:
+    - composer ci:php:lint
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d287045..6c5762aa 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 (#1536)
 - Add support for PostgreSQL 16 (#1271)
 
 ### Changed
diff --git a/composer.json b/composer.json
index 5f8dc4a3..8782600d 100644
--- a/composer.json
+++ b/composer.json
@@ -39,7 +39,7 @@
 		"docs": "https://docs.typo3.org/p/ttn/tea/main/en-us/"
 	},
 	"require": {
-		"php": "~7.4.0 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0",
+		"php": "~7.4.0 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0 || ~8.4.0",
 		"psr/http-message": "^1.0.1",
 		"typo3/cms-core": "^11.5.41 || ^12.4.24",
 		"typo3/cms-extbase": "^11.5.41 || ^12.4.24",
diff --git a/ext_emconf.php b/ext_emconf.php
index 18559e15..05eb8000 100644
--- a/ext_emconf.php
+++ b/ext_emconf.php
@@ -7,7 +7,7 @@
     'category' => 'example',
     'constraints' => [
         'depends' => [
-            'php' => '7.4.0-8.3.99',
+            'php' => '7.4.0-8.4.99',
             'typo3' => '11.5.41-12.4.99',
             'extbase' => '11.5.41-12.4.99',
             'fluid' => '11.5.41-12.4.99',
diff --git a/rector.php b/rector.php
index f75a11bf..554f5a88 100644
--- a/rector.php
+++ b/rector.php
@@ -95,7 +95,7 @@
     ])
     ->withImportNames(true, true, false)
     ->withConfiguredRule(ExtEmConfRector::class, [
-        ExtEmConfRector::PHP_VERSION_CONSTRAINT => '7.4.0-8.3.99',
+        ExtEmConfRector::PHP_VERSION_CONSTRAINT => '7.4.0-8.4.99',
         ExtEmConfRector::TYPO3_VERSION_CONSTRAINT => '11.5.41-12.4.99',
         ExtEmConfRector::ADDITIONAL_VALUES_TO_BE_REMOVED => [],
     ])