diff --git a/custom-css.php b/custom-css.php
index 7efb12c..7b42573 100644
--- a/custom-css.php
+++ b/custom-css.php
@@ -40,7 +40,9 @@ public function onAssetsInitialized()
         $this->grav['assets']->addInlineCss($this->config->get('plugins.custom-css.css_inline'));
 
         foreach($this->config->get('plugins.custom-css.css_files', []) as $file) {
-            $this->grav['assets']->addCss($file['path'], isset($file['priority']) ? $file['priority'] : null);
+            if (trim($file['path']) !== '') {
+                $this->grav['assets']->addCss($file['path'], isset($file['priority']) ? $file['priority'] : null);
+            }
         }
     }
 }