diff --git a/eleventy.config.js b/eleventy.config.js
index 5d8c3af..c599a0d 100644
--- a/eleventy.config.js
+++ b/eleventy.config.js
@@ -363,11 +363,11 @@ export default function (eleventyConfig) {
   });
 
   // Derive OG slug from page.url (reliable) instead of page.fileSlug
-  // (which suffers from Nunjucks race conditions in Eleventy 3.x parallel rendering)
+  // (which suffers from Nunjucks race conditions in Eleventy 3.x parallel rendering).
+  // OG images are named with the full date prefix to match URL segments exactly.
   eleventyConfig.addFilter("ogSlug", (url) => {
     if (!url) return "";
-    const last = url.replace(/\/$/, "").split("/").pop();
-    return last.replace(/^\d{4}-\d{2}-\d{2}-/, "");
+    return url.replace(/\/$/, "").split("/").pop();
   });
 
   // Check if a generated OG image exists for this slug
diff --git a/lib/og.js b/lib/og.js
index dd672ae..b13df90 100644
--- a/lib/og.js
+++ b/lib/og.js
@@ -106,11 +106,12 @@ function formatDate(dateStr) {
 }
 
 /**
- * Strip YYYY-MM-DD- date prefix from filename to match Eleventy's page.fileSlug.
- * Eleventy v3 parses dates from filenames and removes the prefix from fileSlug.
+ * Use the full filename (with date prefix) as the OG image slug.
+ * This matches the URL path segment directly, avoiding Eleventy's page.fileSlug
+ * race condition in Nunjucks parallel rendering.
  */
-function toEleventySlug(filename) {
-  return filename.replace(/^\d{4}-\d{2}-\d{2}-/, "");
+function toOgSlug(filename) {
+  return filename;
 }
 
 function truncateTitle(title, max = 120) {
@@ -307,7 +308,7 @@ export async function generateOgImages(contentDir, cacheDir, siteName) {
       continue;
     }
 
-    const slug = toEleventySlug(basename(filePath, ".md"));
+    const slug = toOgSlug(basename(filePath, ".md"));
     const title = fm.title || fm.name || extractBodyText(raw);
     const date = fm.published || fm.date || "";
     const postType = detectPostType(filePath);