diff --git a/caches/FileCache.php b/caches/FileCache.php
index 3447aa76..a4f48962 100644
--- a/caches/FileCache.php
+++ b/caches/FileCache.php
@@ -41,9 +41,9 @@ class FileCache implements CacheInterface
 
     public function saveData($data): void
     {
-        $writeStream = file_put_contents($this->getCacheFile(), serialize($data));
-        if ($writeStream === false) {
-            throw new \Exception('The cache path is not writeable. You probably want: chown www-data:www-data cache');
+        $bytes = file_put_contents($this->getCacheFile(), serialize($data), LOCK_EX);
+        if ($bytes === false) {
+            throw new \Exception(sprintf('Failed to write to: %s', $this->getCacheFile()));
         }
     }
 
diff --git a/lib/Logger.php b/lib/Logger.php
index 22553dce..b97de978 100644
--- a/lib/Logger.php
+++ b/lib/Logger.php
@@ -77,6 +77,6 @@ final class Logger
 
         // Log to file
         // todo: extract to log handler
-        //file_put_contents('/tmp/rss-bridge.log', $text, FILE_APPEND);
+        // file_put_contents('/tmp/rss-bridge.log', $text, FILE_APPEND | LOCK_EX);
     }
 }