diff --git a/src/Data/ProcessedCodeCoverageData.php b/src/Data/ProcessedCodeCoverageData.php
index 976aaab38..49a103236 100644
--- a/src/Data/ProcessedCodeCoverageData.php
+++ b/src/Data/ProcessedCodeCoverageData.php
@@ -41,6 +41,7 @@
  *      }>
  *  }
  * @phpstan-type FunctionCoverageType array<string, array<string, FunctionCoverageDataType>>
+ * @phpstan-type LineCoverageType array<string, array<int, null|list<TestIdType>>>
  */
 final class ProcessedCodeCoverageData
 {
@@ -48,7 +49,7 @@ final class ProcessedCodeCoverageData
      * Line coverage data.
      * An array of filenames, each having an array of linenumbers, each executable line having an array of testcase ids.
      *
-     * @var array<string, array<int, null|list<TestIdType>>>
+     * @var LineCoverageType
      */
     private array $lineCoverage = [];
 
@@ -111,11 +112,17 @@ public function markCodeAsExecutedByTestCase(string $testCaseId, RawCodeCoverage
         }
     }
 
+    /**
+     * @param LineCoverageType $lineCoverage
+     */
     public function setLineCoverage(array $lineCoverage): void
     {
         $this->lineCoverage = $lineCoverage;
     }
 
+    /**
+     * @return LineCoverageType
+     */
     public function lineCoverage(): array
     {
         ksort($this->lineCoverage);
@@ -123,11 +130,17 @@ public function lineCoverage(): array
         return $this->lineCoverage;
     }
 
+    /**
+     * @param FunctionCoverageType $functionCoverage
+     */
     public function setFunctionCoverage(array $functionCoverage): void
     {
         $this->functionCoverage = $functionCoverage;
     }
 
+    /**
+     * @return FunctionCoverageType
+     */
     public function functionCoverage(): array
     {
         ksort($this->functionCoverage);
@@ -135,6 +148,9 @@ public function functionCoverage(): array
         return $this->functionCoverage;
     }
 
+    /**
+     * @return array<string>
+     */
     public function coveredFiles(): array
     {
         ksort($this->lineCoverage);
diff --git a/src/Node/Builder.php b/src/Node/Builder.php
index 19fc3a24d..9a2efe145 100644
--- a/src/Node/Builder.php
+++ b/src/Node/Builder.php
@@ -140,6 +140,9 @@ private function buildDirectoryStructure(ProcessedCodeCoverageData $data): array
     {
         $result = [];
 
+        $lineCoverage     = $data->lineCoverage();
+        $functionCoverage = $data->functionCoverage();
+
         foreach ($data->coveredFiles() as $originalPath) {
             $path    = explode(DIRECTORY_SEPARATOR, $originalPath);
             $pointer = &$result;
@@ -156,8 +159,8 @@ private function buildDirectoryStructure(ProcessedCodeCoverageData $data): array
             }
 
             $pointer = [
-                'lineCoverage'     => $data->lineCoverage()[$originalPath] ?? [],
-                'functionCoverage' => $data->functionCoverage()[$originalPath] ?? [],
+                'lineCoverage'     => $lineCoverage[$originalPath] ?? [],
+                'functionCoverage' => $functionCoverage[$originalPath] ?? [],
             ];
         }
 
@@ -203,12 +206,14 @@ private function buildDirectoryStructure(ProcessedCodeCoverageData $data): array
      */
     private function reducePaths(ProcessedCodeCoverageData $coverage): string
     {
-        if ($coverage->coveredFiles() === []) {
+        $coveredFiles = $coverage->coveredFiles();
+
+        if ($coveredFiles === []) {
             return '.';
         }
 
         $commonPath = '';
-        $paths      = $coverage->coveredFiles();
+        $paths      = $coveredFiles;
 
         if (count($paths) === 1) {
             $commonPath = dirname($paths[0]) . DIRECTORY_SEPARATOR;
@@ -260,7 +265,7 @@ private function reducePaths(ProcessedCodeCoverageData $coverage): string
             }
         }
 
-        $original = $coverage->coveredFiles();
+        $original = $coveredFiles;
         $max      = count($original);
 
         for ($i = 0; $i < $max; $i++) {