diff --git a/src/Core/Config/Cache/ConfigCache.php b/src/Core/Config/Cache/ConfigCache.php
index cf50b43d4f..cb299eb330 100644
--- a/src/Core/Config/Cache/ConfigCache.php
+++ b/src/Core/Config/Cache/ConfigCache.php
@@ -30,7 +30,7 @@ class ConfigCache implements IConfigCache, IPConfigCache
 		$categories = array_keys($config);
 
 		foreach ($categories as $category) {
-			if (isset($config[$category]) && is_array($config[$category])) {
+			if (is_array($config[$category])) {
 				$keys = array_keys($config[$category]);
 
 				foreach ($keys as $key) {
diff --git a/src/Core/Config/Cache/ConfigCacheLoader.php b/src/Core/Config/Cache/ConfigCacheLoader.php
index 8a2dc2b1e2..55f18681ce 100644
--- a/src/Core/Config/Cache/ConfigCacheLoader.php
+++ b/src/Core/Config/Cache/ConfigCacheLoader.php
@@ -110,18 +110,18 @@ class ConfigCacheLoader
 			$a->config = [];
 			include $filePath;
 
-			$htconfigAr = array_keys($a->config);
+			$htConfigCategories = array_keys($a->config);
 
 			// map the legacy configuration structure to the current structure
-			foreach ($htconfigAr as $htconfig) {
-				if (isset($a->config[$htconfig]) && is_array($a->config[$htconfig])) {
-					$keys = array_keys($a->config[$htconfig]);
+			foreach ($htConfigCategories as $htConfigCategory) {
+				if (is_array($a->config[$htConfigCategory])) {
+					$keys = array_keys($a->config[$htConfigCategory]);
 
 					foreach ($keys as $key) {
-						$config[$htconfig][$key] = $a->config[$htconfig][$key];
+						$config[$htConfigCategory][$key] = $a->config[$htConfigCategory][$key];
 					}
 				} else {
-					$config['config'][$htconfig] = $a->config[$htconfig];
+					$config['config'][$htConfigCategory] = $a->config[$htConfigCategory];
 				}
 			}