diff --git a/packages/docusaurus/src/server/__tests__/configValidation.test.ts b/packages/docusaurus/src/server/__tests__/configValidation.test.ts
index ffe402504593..9297df2db422 100644
--- a/packages/docusaurus/src/server/__tests__/configValidation.test.ts
+++ b/packages/docusaurus/src/server/__tests__/configValidation.test.ts
@@ -94,7 +94,18 @@ describe('normalizeConfig', () => {
         url: 1,
       }),
     ).toThrowErrorMatchingInlineSnapshot(`
-      ""url" contains an invalid value
+      ""url" must be a string
+      "
+    `);
+  });
+
+  it('throws for invalid URL', () => {
+    expect(() =>
+      normalizeConfig({
+        url: 'mysite.com',
+      }),
+    ).toThrowErrorMatchingInlineSnapshot(`
+      ""mysite.com" does not look like a valid URL. Make sure it has a protocol; for example, "https://example.com".
       "
     `);
   });
diff --git a/packages/docusaurus/src/server/configValidation.ts b/packages/docusaurus/src/server/configValidation.ts
index c4c9903c666d..ff8da9bd96eb 100644
--- a/packages/docusaurus/src/server/configValidation.ts
+++ b/packages/docusaurus/src/server/configValidation.ts
@@ -12,7 +12,7 @@ import {
   addTrailingSlash,
   removeTrailingSlash,
 } from '@docusaurus/utils';
-import {Joi, URISchema, printWarning} from '@docusaurus/utils-validation';
+import {Joi, printWarning} from '@docusaurus/utils-validation';
 import type {DocusaurusConfig, I18nConfig} from '@docusaurus/types';
 
 const DEFAULT_I18N_LOCALE = 'en';
@@ -152,17 +152,25 @@ const I18N_CONFIG_SCHEMA = Joi.object<I18nConfig>({
   .optional()
   .default(DEFAULT_I18N_CONFIG);
 
-const SiteUrlSchema = URISchema.required().custom((value: string, helpers) => {
-  try {
-    const {pathname} = new URL(String(value));
-    if (pathname !== '/') {
-      helpers.warn('docusaurus.configValidationWarning', {
-        warningMessage: `The url is not supposed to contain a sub-path like '${pathname}'. Please use the baseUrl field for sub-paths.`,
-      });
+const SiteUrlSchema = Joi.string()
+  .required()
+  .custom((value: string, helpers) => {
+    try {
+      const {pathname} = new URL(value);
+      if (pathname !== '/') {
+        helpers.warn('docusaurus.configValidationWarning', {
+          warningMessage: `The url is not supposed to contain a sub-path like '${pathname}'. Please use the baseUrl field for sub-paths.`,
+        });
+      }
+    } catch {
+      return helpers.error('any.invalid');
     }
-  } catch {}
-  return removeTrailingSlash(value);
-});
+    return removeTrailingSlash(value);
+  })
+  .messages({
+    'any.invalid':
+      '"{#value}" does not look like a valid URL. Make sure it has a protocol; for example, "https://example.com".',
+  });
 
 // TODO move to @docusaurus/utils-validation
 export const ConfigSchema = Joi.object<DocusaurusConfig>({