diff --git a/lighthouse-core/config/config.js b/lighthouse-core/config/config.js
index 40651ccbda6a..9de9ab95309e 100644
--- a/lighthouse-core/config/config.js
+++ b/lighthouse-core/config/config.js
@@ -63,10 +63,15 @@ function validateCategories(categories, audits, groups) {
       }
 
       const auditImpl = audit.implementation;
-      if (categoryId === 'accessibility' && !auditRef.group && !auditImpl.meta.manual) {
+      const isManual = auditImpl.meta.scoreDisplayMode === 'manual';
+      if (categoryId === 'accessibility' && !auditRef.group && !isManual) {
         throw new Error(`${auditRef.id} accessibility audit does not have a group`);
       }
 
+      if (auditRef.weight > 0 && isManual) {
+        throw new Error(`${auditRef.id} is manual but has a positive weight`);
+      }
+
       if (auditRef.group && !groups[auditRef.group]) {
         throw new Error(`${auditRef.id} references unknown group ${auditRef.group}`);
       }
diff --git a/lighthouse-core/test/config/config-test.js b/lighthouse-core/test/config/config-test.js
index 156509a144f0..15f2fb775522 100644
--- a/lighthouse-core/test/config/config-test.js
+++ b/lighthouse-core/test/config/config-test.js
@@ -271,6 +271,19 @@ describe('Config', () => {
     }), /unknown group missing-group/);
   });
 
+  it('throws when a manual audit has weight', () => {
+    return assert.throws(_ => new Config({
+      audits: ['manual/pwa-cross-browser'],
+      categories: {
+        accessibility: {
+          audits: [
+            {id: 'pwa-cross-browser', weight: 10},
+          ],
+        },
+      },
+    }), /cross-browser .*has a positive weight/);
+  });
+
   it('filters the config', () => {
     const config = new Config({
       settings: {