diff --git a/src/Doctrine/Annotation/DocLexer.php b/src/Doctrine/Annotation/DocLexer.php
index b451d00bfac..ef1878ea241 100644
--- a/src/Doctrine/Annotation/DocLexer.php
+++ b/src/Doctrine/Annotation/DocLexer.php
@@ -75,7 +75,7 @@ final class DocLexer
 
     private int $peek = 0;
 
-    private ?string $regex;
+    private ?string $regex = null;
 
     public function setInput(string $input): void
     {
diff --git a/src/Fixer/Alias/BacktickToShellExecFixer.php b/src/Fixer/Alias/BacktickToShellExecFixer.php
index 351cdad72a1..b59457eae9b 100644
--- a/src/Fixer/Alias/BacktickToShellExecFixer.php
+++ b/src/Fixer/Alias/BacktickToShellExecFixer.php
@@ -96,8 +96,7 @@ private function fixBackticks(Tokens $tokens, array $backtickTokens): void
         // Track indices for final override
         ksort($backtickTokens);
         $openingBacktickIndex = key($backtickTokens);
-        end($backtickTokens);
-        $closingBacktickIndex = key($backtickTokens);
+        $closingBacktickIndex = array_key_last($backtickTokens);
 
         // Strip enclosing backticks
         array_shift($backtickTokens);
diff --git a/src/Tokenizer/Analyzer/Analysis/TypeAnalysis.php b/src/Tokenizer/Analyzer/Analysis/TypeAnalysis.php
index a332b244271..27bf893f384 100644
--- a/src/Tokenizer/Analyzer/Analysis/TypeAnalysis.php
+++ b/src/Tokenizer/Analyzer/Analysis/TypeAnalysis.php
@@ -57,7 +57,7 @@ final class TypeAnalysis implements StartEndTokenAwareAnalysis
 
     private int $endIndex;
 
-    private bool $nullable;
+    private bool $nullable = false;
 
     /**
      * @param ($startIndex is null ? null : int) $endIndex
@@ -65,7 +65,6 @@ final class TypeAnalysis implements StartEndTokenAwareAnalysis
     public function __construct(string $name, int $startIndex = null, int $endIndex = null)
     {
         $this->name = $name;
-        $this->nullable = false;
 
         if (str_starts_with($name, '?')) {
             $this->name = substr($name, 1);
diff --git a/tests/Runner/RunnerTest.php b/tests/Runner/RunnerTest.php
index 13c9c57516f..c1195119a21 100644
--- a/tests/Runner/RunnerTest.php
+++ b/tests/Runner/RunnerTest.php
@@ -166,7 +166,7 @@ public function testThatDiffedFileIsPassedToDiffer(): void
     private function createDifferDouble(): DifferInterface
     {
         return new class() implements DifferInterface {
-            public ?\SplFileInfo $passedFile;
+            public ?\SplFileInfo $passedFile = null;
 
             public function diff(string $old, string $new, \SplFileInfo $file = null): string
             {
diff --git a/tests/Test/AbstractFixerTestCase.php b/tests/Test/AbstractFixerTestCase.php
index ed699561e73..01269dc6a6a 100644
--- a/tests/Test/AbstractFixerTestCase.php
+++ b/tests/Test/AbstractFixerTestCase.php
@@ -207,8 +207,7 @@ final public function testFixerDefinitions(): void
 
         if ($fixerIsConfigurable) {
             if (isset($configSamplesProvided['default'])) {
-                reset($configSamplesProvided);
-                self::assertSame('default', key($configSamplesProvided), sprintf('[%s] First sample must be for the default configuration.', $fixerName));
+                self::assertSame('default', array_key_first($configSamplesProvided), sprintf('[%s] First sample must be for the default configuration.', $fixerName));
             } elseif (!isset($this->allowedFixersWithoutDefaultCodeSample[$fixerName])) {
                 self::assertArrayHasKey($fixerName, $this->allowedRequiredOptions, sprintf('[%s] Has no sample for default configuration.', $fixerName));
             }