diff --git a/assets/js/app.js b/assets/js/app.js
index 8c3c529..c7e1c97 100644
--- a/assets/js/app.js
+++ b/assets/js/app.js
@@ -91,8 +91,9 @@
     const path = location.pathname;
     tabs.forEach(btn => {
       const cat = btn.dataset.cat;
-      const active = (cat === 'All' && (path === '/' || path.startsWith('/issue') || path === '/posts/'))
-        || (cat !== 'All' && path.toLowerCase().includes(cat.toLowerCase().replace(/\s+/g, '-').replace(/[^a-z0-9-]/g, '')));
+      const slug = cat.toLowerCase().replace(/\s+/g, '-').replace(/[^a-z0-9-]/g, '');
+      const active = (cat === 'All' && (path === '/' || path.startsWith('/issues') || path === '/posts/'))
+        || (cat !== 'All' && path === `/categories/${slug}/`);
       btn.setAttribute('aria-pressed', active ? 'true' : 'false');
     });
   }
diff --git a/static/js/app.js b/static/js/app.js
index 8c3c529..c7e1c97 100644
--- a/static/js/app.js
+++ b/static/js/app.js
@@ -91,8 +91,9 @@
     const path = location.pathname;
     tabs.forEach(btn => {
       const cat = btn.dataset.cat;
-      const active = (cat === 'All' && (path === '/' || path.startsWith('/issue') || path === '/posts/'))
-        || (cat !== 'All' && path.toLowerCase().includes(cat.toLowerCase().replace(/\s+/g, '-').replace(/[^a-z0-9-]/g, '')));
+      const slug = cat.toLowerCase().replace(/\s+/g, '-').replace(/[^a-z0-9-]/g, '');
+      const active = (cat === 'All' && (path === '/' || path.startsWith('/issues') || path === '/posts/'))
+        || (cat !== 'All' && path === `/categories/${slug}/`);
       btn.setAttribute('aria-pressed', active ? 'true' : 'false');
     });
   }