diff --git a/packages/docusaurus/src/server/__tests__/configValidation.test.ts b/packages/docusaurus/src/server/__tests__/configValidation.test.ts
index 23bf04fb74..c6eb2e39d2 100644
--- a/packages/docusaurus/src/server/__tests__/configValidation.test.ts
+++ b/packages/docusaurus/src/server/__tests__/configValidation.test.ts
@@ -42,6 +42,7 @@ describe('normalizeConfig', () => {
           src: `/analytics.js`,
           async: true,
           defer: true,
+          'data-domain': 'xyz', // See https://github.com/facebook/docusaurus/issues/3378
         },
       ],
       stylesheets: [
diff --git a/packages/docusaurus/src/server/configValidation.ts b/packages/docusaurus/src/server/configValidation.ts
index cf5b5ad42a..f4fbe9bdb3 100644
--- a/packages/docusaurus/src/server/configValidation.ts
+++ b/packages/docusaurus/src/server/configValidation.ts
@@ -77,7 +77,9 @@ const ConfigSchema = Joi.object({
       src: Joi.string().required(),
       async: Joi.bool(),
       defer: Joi.bool(),
-    }),
+    })
+      // See https://github.com/facebook/docusaurus/issues/3378
+      .unknown(),
   ),
   stylesheets: Joi.array().items(
     Joi.string(),