diff --git a/classes/cache_config.php b/classes/cache_config.php
index a6a66fe..5294311 100644
--- a/classes/cache_config.php
+++ b/classes/cache_config.php
@@ -297,7 +297,7 @@ private function generate_mode_mapping($rules): array {
                 // Check if the rule has any conditions, if not it will be set
                 // as the default store as it is considered the broadest rule.
                 if (empty($lastrule['conditions'])) {
-                    $modemapping['store'] = $lastrule['stores'];
+                    $modemapping['store'] = reset($lastrule['stores']);
                 }
             }
             return $modemapping;
diff --git a/tests/fixtures/mode_mappings_data.php b/tests/fixtures/mode_mappings_data.php
index f49d110..5164d9b 100644
--- a/tests/fixtures/mode_mappings_data.php
+++ b/tests/fixtures/mode_mappings_data.php
@@ -37,9 +37,7 @@
 $generatedmodemappingagainstdefinitionmatchtoprulesetexpected = array(
     array(
         'mode' => cache_store::MODE_APPLICATION,
-        'store' => array(
-            'file-test'
-        ),
+        'store' => 'file-test',
         'sort' => -1
     ),
     array(