diff --git a/_includes/layouts/base.njk b/_includes/layouts/base.njk
index 3ded1d2..5bc99b3 100644
--- a/_includes/layouts/base.njk
+++ b/_includes/layouts/base.njk
@@ -23,13 +23,17 @@
   <meta property="og:type" content="{% if page.url == '/' %}website{% else %}article{% endif %}">
   <meta property="og:description" content="{{ ogDesc }}">
   <meta name="description" content="{{ ogDesc }}">
-  {# Compute OG slug from page.url — NOT permalink or eleventyComputed values.
-     Eleventy 3.x parallel rendering (issue #3183) cross-contaminates eleventyComputed
-     return values across pages. permalink is set by eleventyComputed and is UNRELIABLE.
-     page.url is set by Eleventy's internal pipeline and IS correct in templates
-     (verified: og:url uses page.url and always shows the right URL). #}
-  {% set _ogSlug = page.url | ogSlug %}
+  {# Compute OG slug inline from page.url using string ops — avoid filter calls
+     which may be affected by Eleventy 3.x parallel rendering race conditions.
+     page.url is correct (verified via og:url), compute slug inline. #}
+  {% set _urlParts = page.url.split('/') | reject("equalto", "") | list %}
+  {% if _urlParts | length >= 5 %}
+    {% set _ogSlug = _urlParts[1] + '-' + _urlParts[2] + '-' + _urlParts[3] + '-' + _urlParts[4] %}
+  {% else %}
+    {% set _ogSlug = _urlParts | last | default("") %}
+  {% endif %}
   {% set _hasOg = _ogSlug | hasOgImage %}
+  <!-- debug:og page.url={{ page.url }} permalink={{ permalink }} ogSlug={{ _ogSlug }} -->
   {% if ogPhoto and ogPhoto != "" and (ogPhoto | length) > 10 %}
   <meta property="og:image" content="{% if 'http' in ogPhoto %}{{ ogPhoto }}{% else %}{{ site.url }}{% if ogPhoto[0] != '/' %}/{% endif %}{{ ogPhoto }}{% endif %}">
   {% elif image and image != "" and (image | length) > 10 %}