diff --git a/packages/frontend/src/components/dictionary/WordDetailModal.tsx b/packages/frontend/src/components/dictionary/WordDetailModal.tsx
index d58c5f9..7ee5532 100644
--- a/packages/frontend/src/components/dictionary/WordDetailModal.tsx
+++ b/packages/frontend/src/components/dictionary/WordDetailModal.tsx
@@ -57,7 +57,7 @@ export function WordDetailModal({ term, open, onClose, onAddToSentence }: WordDe
   const imageMedia = term.media?.find(m => m.kind === 'IMAGE' || m.kind === 'ILLUSTRATION');
 
   // Construct full video URL
-  const API_URL = import.meta.env.VITE_API_URL || 'http://localhost:3000';
+  const API_URL = import.meta.env.VITE_API_URL !== undefined ? import.meta.env.VITE_API_URL : 'http://localhost:3000';
   const videoUrl = videoMedia?.url.startsWith('http')
     ? videoMedia.url
     : `${API_URL}${videoMedia?.url}`;