diff --git a/frontend/src/components/MessageAttachment.svelte b/frontend/src/components/MessageAttachment.svelte
index f255668..3d54b86 100644
--- a/frontend/src/components/MessageAttachment.svelte
+++ b/frontend/src/components/MessageAttachment.svelte
@@ -92,7 +92,7 @@
     <img loading="lazy" decoding="async" width="{ attachment.width }" height="{ attachment.height }" class="attachment media" alt="Attachment" src="{ attachmentUrl(attachment.file) }">
 {:else if renderAs === AttachmentRenderAs.Video}
     <!-- svelte-ignore a11y-media-has-caption -->
-    <video controls="controls" class="attachment media" src="{ attachmentUrl(attachment.file) }"></video>
+    <video controls="controls" class="attachment media" src="{ attachmentUrl(attachment.file) }" width=400 height=400></video>
 {:else if renderAs === AttachmentRenderAs.DownloadableFile}
     <div class="attachment attachment-card">
         <div class="attachment-filename">{ attachment.file_name }</div>