diff --git a/composer.json b/composer.json
index e2763b156..a2cbef0e8 100644
--- a/composer.json
+++ b/composer.json
@@ -55,7 +55,7 @@
         "assertwell/phpunit-global-state": "^0.2",
         "composer/xdebug-handler": "^2.0",
         "dg/bypass-finals": "^1.3",
-        "friendsofphp/php-cs-fixer": "^3.0",
+        "friendsofphp/php-cs-fixer": "^3.4",
         "guzzlehttp/guzzle": "^7.4",
         "guzzlehttp/psr7": "^2.1",
         "mikey179/vfsstream": "^1.6",
diff --git a/tests/Context/Unit/Propagation/ArrayAccessGetterSetterTest.php b/tests/Context/Unit/Propagation/ArrayAccessGetterSetterTest.php
index 495f7a9ef..a20806647 100644
--- a/tests/Context/Unit/Propagation/ArrayAccessGetterSetterTest.php
+++ b/tests/Context/Unit/Propagation/ArrayAccessGetterSetterTest.php
@@ -84,11 +84,11 @@ public function offsetGet($offset)
             {
             }
 
-            public function offsetSet($offset, $value)
+            public function offsetSet($offset, $value): void
             {
             }
 
-            public function offsetUnset($offset)
+            public function offsetUnset($offset): void
             {
             }
 
diff --git a/tests/SDK/Integration/ParentBasedTest.php b/tests/SDK/Integration/ParentBasedTest.php
index 164b56e47..a83e770ee 100644
--- a/tests/SDK/Integration/ParentBasedTest.php
+++ b/tests/SDK/Integration/ParentBasedTest.php
@@ -37,7 +37,7 @@ public function testParentBased(
         ?SamplerInterface $remoteParentNotSampled = null,
         ?SamplerInterface $localParentSampled = null,
         ?SamplerInterface $localParentNotSampled = null,
-        $expectedDdecision
+        ?int $expectedDecision = null
     ): void {
         $rootSampler = $this->createMockSamplerNeverInvoked();
 
@@ -48,7 +48,7 @@ public function testParentBased(
             'test.opentelemetry.io',
             API\SpanKind::KIND_INTERNAL
         );
-        $this->assertEquals($expectedDdecision, $decision->getDecision());
+        $this->assertEquals($expectedDecision, $decision->getDecision());
     }
 
     public function parentContextData(): array