diff --git a/src/ProcessedCodeCoverageData.php b/src/ProcessedCodeCoverageData.php
index 1966fcf12..1ed29ad52 100644
--- a/src/ProcessedCodeCoverageData.php
+++ b/src/ProcessedCodeCoverageData.php
@@ -116,6 +116,8 @@ public function functionCoverage(): array
 
     public function coveredFiles(): array
     {
+        ksort($this->lineCoverage);
+
         return array_keys($this->lineCoverage);
     }