diff --git a/packages/docusaurus-utils/src/__tests__/index.test.ts b/packages/docusaurus-utils/src/__tests__/index.test.ts
index a47fc0f15e1a..546ce167cc88 100644
--- a/packages/docusaurus-utils/src/__tests__/index.test.ts
+++ b/packages/docusaurus-utils/src/__tests__/index.test.ts
@@ -254,6 +254,10 @@ describe('load utils', () => {
         input: ['/test/', '/', 'ro', 'doc1'],
         output: '/test/ro/doc1',
       },
+      {
+        input: ['/', '/', '2020/02/29/leap-day'],
+        output: '/2020/02/29/leap-day',
+      },
       {
         input: ['', '/', 'ko', 'hello'],
         output: '/ko/hello',
diff --git a/packages/docusaurus-utils/src/index.ts b/packages/docusaurus-utils/src/index.ts
index 2309c680beda..3336bbdfbe05 100644
--- a/packages/docusaurus-utils/src/index.ts
+++ b/packages/docusaurus-utils/src/index.ts
@@ -256,6 +256,9 @@ export function normalizeUrl(rawUrls: string[]): string {
   // Dedupe forward slashes in the entire path, avoiding protocol slashes.
   str = str.replace(/([^:]\/)\/+/g, '$1');
 
+  // Dedupe forward slashes at the beginning of the path.
+  str = str.replace(/^\/+/g, '/');
+
   return str;
 }