diff --git a/README.md b/README.md
index cb372ec..db16998 100644
--- a/README.md
+++ b/README.md
@@ -74,6 +74,8 @@ yarn node -e "require('sharp')('static\\img\\community-social-card.svg').png().t
 
 The site configuration uses the PNG for Open Graph and Twitter cards, since social crawlers do not
 reliably support SVG previews. The image is intentionally fixed to the light brand palette.
+If its dimensions change, update `og:image:width` and `og:image:height` in
+[the site configuration](docusaurus.config.ts) to match the exported PNG.
 
 ## Deployment
 
diff --git a/docusaurus.config.ts b/docusaurus.config.ts
index c59c47e..b30779e 100644
--- a/docusaurus.config.ts
+++ b/docusaurus.config.ts
@@ -110,6 +110,10 @@ const config: Config = {
     /** @type {import('@docusaurus/preset-classic').ThemeConfig} */
     {
       image: 'img/community-social-card.png',
+      metadata: [
+        { property: 'og:image:width', content: '1200' },
+        { property: 'og:image:height', content: '630' },
+      ],
       colorMode: {
         defaultMode: 'dark',
         disableSwitch: false,