diff --git a/src/MetaLoader.php b/src/MetaLoader.php
index e7faf30..d0f4098 100644
--- a/src/MetaLoader.php
+++ b/src/MetaLoader.php
@@ -214,7 +214,7 @@ public function loadSource(array $source): void
     /**
      * @param \SimpleSAML\Metadata\SAMLParser $entity
      * @param array $source
-     * @bool
+     * @return bool
      */
     private function processCertificates(Metadata\SAMLParser $entity, array $source): bool
     {
@@ -234,7 +234,7 @@ private function processCertificates(Metadata\SAMLParser $entity, array $source)
     /**
      * @param \SimpleSAML\Metadata\SAMLParser $entity
      * @param array $source
-     * @bool
+     * @return bool
      */
     private function processBlacklist(Metadata\SAMLParser $entity, array $source): bool
     {
@@ -251,7 +251,7 @@ private function processBlacklist(Metadata\SAMLParser $entity, array $source): b
     /**
      * @param \SimpleSAML\Metadata\SAMLParser $entity
      * @param array $source
-     * @bool
+     * @return bool
      */
     private function processWhitelist(Metadata\SAMLParser $entity, array $source): bool
     {
@@ -268,7 +268,7 @@ private function processWhitelist(Metadata\SAMLParser $entity, array $source): b
     /**
      * @param \SimpleSAML\Metadata\SAMLParser $entity
      * @param array $source
-     * @bool
+     * @return bool
      */
     private function processAttributeWhitelist(Metadata\SAMLParser $entity, array $source): bool
     {
diff --git a/src/MetaRefresh.php b/src/MetaRefresh.php
index 86770f1..1e6c1b7 100644
--- a/src/MetaRefresh.php
+++ b/src/MetaRefresh.php
@@ -66,7 +66,7 @@ public function runRefresh(string $crontag = null): void
                 throw new Exception("Invalid outputDir specified.");
             }
 
-            $outputFormat = $set->getValueValidate('outputFormat', ['flatfile', 'serialize', 'pdo'], 'flatfile');
+            $outputFormat = $set->getOptionalValueValidate('outputFormat', ['flatfile', 'serialize', 'pdo'], 'flatfile');
 
             $oldMetadataSrc = MetaDataStorageSource::getSource([
                 'type' => $outputFormat,