diff --git a/docusaurus-search-local/src/server/utils/buildIndex.ts b/docusaurus-search-local/src/server/utils/buildIndex.ts
index 1c16be47..a18319f2 100644
--- a/docusaurus-search-local/src/server/utils/buildIndex.ts
+++ b/docusaurus-search-local/src/server/utils/buildIndex.ts
@@ -36,41 +36,45 @@ export function buildIndex(
     require("lunr-languages/lunr.multi")(lunr);
   }
 
-  return allDocuments.map((documents) => ({
-    documents,
-    index: lunr(function () {
-      if (language.length > 1) {
-        this.use((lunr as any).multiLanguage(...language));
-      } else if (language[0] !== "en") {
-        this.use((lunr as any)[language[0]]);
-      }
+  // Some documents may be empty (unset array item), which is not mapped.
+  return new Array<SearchDocument[] | null>(allDocuments.length)
+    .fill(null)
+    .map((_doc, index) => allDocuments[index] ?? [])
+    .map((documents) => ({
+      documents,
+      index: lunr(function () {
+        if (language.length > 1) {
+          this.use((lunr as any).multiLanguage(...language));
+        } else if (language[0] !== "en") {
+          this.use((lunr as any)[language[0]]);
+        }
 
-      if (removeDefaultStopWordFilter) {
-        // Sometimes we need no English stop words,
-        // since they are almost all programming code.
-        this.pipeline.remove(lunr.stopWordFilter);
-      }
+        if (removeDefaultStopWordFilter) {
+          // Sometimes we need no English stop words,
+          // since they are almost all programming code.
+          this.pipeline.remove(lunr.stopWordFilter);
+        }
 
-      if (removeDefaultStemmer) {
-        this.pipeline.remove(lunr.stemmer);
-      }
+        if (removeDefaultStemmer) {
+          this.pipeline.remove(lunr.stemmer);
+        }
 
-      // Override tokenizer when language `zh` is enabled.
-      if (language.includes("zh")) {
-        this.tokenizer = (lunr as any).zh.tokenizer;
-      }
+        // Override tokenizer when language `zh` is enabled.
+        if (language.includes("zh")) {
+          this.tokenizer = (lunr as any).zh.tokenizer;
+        }
 
-      this.ref("i");
-      this.field("t");
-      this.metadataWhitelist = ["position"];
+        this.ref("i");
+        this.field("t");
+        this.metadataWhitelist = ["position"];
 
-      documents.forEach((doc) => {
-        this.add({
-          ...doc,
-          // The ref must be a string.
-          i: doc.i.toString(),
+        documents.forEach((doc) => {
+          this.add({
+            ...doc,
+            // The ref must be a string.
+            i: doc.i.toString(),
+          });
         });
-      });
-    }),
-  }));
+      }),
+    }));
 }
diff --git a/docusaurus-search-local/src/server/utils/postBuildFactory.ts b/docusaurus-search-local/src/server/utils/postBuildFactory.ts
index ab4bc917..689118c1 100644
--- a/docusaurus-search-local/src/server/utils/postBuildFactory.ts
+++ b/docusaurus-search-local/src/server/utils/postBuildFactory.ts
@@ -48,17 +48,17 @@ export function postBuildFactory(
           for (const doc of documents) {
             if (doc.u.startsWith(baseUrl)) {
               const uri = doc.u.substring(baseUrl.length);
-              let matchedPathes: string[] = [];
+              const matchedPaths: string[] = [];
               for (const _path of searchContextByPaths) {
                 const path = typeof _path === "string" ? _path : _path.path;
                 if (uri === path || uri.startsWith(`${path}/`)) {
-                  matchedPathes.push(path);
+                  matchedPaths.push(path);
                 }
               }
-              for (const matchedPath of matchedPathes) {
+              for (const matchedPath of matchedPaths) {
                 let dirAllDocs = docsByDirMap.get(matchedPath);
                 if (!dirAllDocs) {
-                  dirAllDocs = [];
+                  dirAllDocs = new Array(allDocuments.length);
                   docsByDirMap.set(matchedPath, dirAllDocs);
                 }
                 let dirDocs = dirAllDocs[docIndex];
@@ -67,7 +67,10 @@ export function postBuildFactory(
                 }
                 dirDocs.push(doc);
               }
-              if (matchedPathes.length > 0 && !useAllContextsWithNoSearchContext) {
+              if (
+                matchedPaths.length > 0 &&
+                !useAllContextsWithNoSearchContext
+              ) {
                 continue;
               }
             }
@@ -75,12 +78,6 @@ export function postBuildFactory(
           }
           docIndex++;
         }
-        for (const [k, v] of docsByDirMap) {
-          const docsNotEmpty = v.filter((d) => !!d);
-          if (docsNotEmpty.length < v.length) {
-            docsByDirMap.set(k, docsNotEmpty);
-          }
-        }
       } else {
         docsByDirMap.set("", allDocuments);
       }