diff --git a/src/Analyser/ResultCache/ResultCacheManager.php b/src/Analyser/ResultCache/ResultCacheManager.php
index 80ea03ac06..ff75f5a0f0 100644
--- a/src/Analyser/ResultCache/ResultCacheManager.php
+++ b/src/Analyser/ResultCache/ResultCacheManager.php
@@ -312,18 +312,27 @@ public function restore(array $allAnalysedFiles, bool $debug, bool $onlyFiles, ?
 	}
 
 	/**
-	 * @param mixed[] $cachedMeta
-	 * @param mixed[] $currentMeta
+	 * @param mixed[]|null $projectConfig
 	 */
-	private function isMetaDifferent(array $cachedMeta, array $currentMeta): bool
+	private function normalizeMetaProjectConfig(?array $projectConfig): ?string
 	{
-		$projectConfig = $currentMeta['projectConfig'];
 		if ($projectConfig !== null) {
-			ksort($currentMeta['projectConfig']);
+			ksort($projectConfig);
 
-			$currentMeta['projectConfig'] = Neon::encode($currentMeta['projectConfig']);
+			return Neon::encode($projectConfig);
 		}
 
+		return null;
+	}
+
+	/**
+	 * @param mixed[] $cachedMeta
+	 * @param mixed[] $currentMeta
+	 */
+	private function isMetaDifferent(array $cachedMeta, array $currentMeta): bool
+	{
+		$currentMeta['projectConfig'] = $this->normalizeMetaProjectConfig($currentMeta['projectConfig']);
+
 		return $cachedMeta !== $currentMeta;
 	}
 
@@ -337,6 +346,10 @@ private function getMetaKeyDifferences(array $cachedMeta, array $currentMeta): a
 	{
 		$diffs = [];
 		foreach ($cachedMeta as $key => $value) {
+			if ($key === 'projectConfig') {
+				$value = $this->normalizeMetaProjectConfig($value);
+			}
+
 			if (!array_key_exists($key, $currentMeta)) {
 				$diffs[] = $key;
 				continue;