diff --git a/CHANGELOG.md b/CHANGELOG.md
index 639f08b9..9e50afaa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
-...
+ - Add forward compatibility with Symfony 5 (#235, thanks to @garak)
 
 ## 3.1.0 - 2019-07-02
  - Add support for Symfony 2.8 (#233, thanks to @nocive)
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 015c04d9..6f25af07 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -21,7 +21,7 @@ class Configuration implements ConfigurationInterface
      * @throws \InvalidArgumentException
      * @throws \RuntimeException
      */
-    public function getConfigTreeBuilder()
+    public function getConfigTreeBuilder(): TreeBuilder
     {
         $treeBuilder = new TreeBuilder('sentry');
         /** @var ArrayNodeDefinition $rootNode */
diff --git a/src/DependencyInjection/SentryExtension.php b/src/DependencyInjection/SentryExtension.php
index 970ba1bf..751387e5 100644
--- a/src/DependencyInjection/SentryExtension.php
+++ b/src/DependencyInjection/SentryExtension.php
@@ -32,7 +32,7 @@ class SentryExtension extends Extension
      *
      * @throws InvalidConfigurationException
      */
-    public function load(array $configs, ContainerBuilder $container)
+    public function load(array $configs, ContainerBuilder $container): void
     {
         $configuration = new Configuration();
         $processedConfiguration = $this->processConfiguration($configuration, $configs);