diff --git a/lib/extend/helper.ts b/lib/extend/helper.ts
index f167282371..6bfe45be4d 100644
--- a/lib/extend/helper.ts
+++ b/lib/extend/helper.ts
@@ -1,12 +1,49 @@
+import Hexo from '../hexo';
+import { PageSchema } from '../types';
+import * as hutil from 'hexo-util';
+
+interface HexoContext extends Hexo {
+  // get current page information
+  // https://github.com/dimaslanjaka/hexo-renderers/blob/147340f6d03a8d3103e9589ddf86778ed7f9019b/src/helper/related-posts.ts#L106-L113
+  page?: PageSchema;
+
+  // hexo-util shims
+  url_for: typeof hutil.url_for;
+  full_url_for: typeof hutil.full_url_for;
+  relative_url: typeof hutil.relative_url;
+  slugize: typeof hutil.slugize;
+  escapeDiacritic: typeof hutil.escapeDiacritic;
+  escapeHTML: typeof hutil.escapeHTML;
+  unescapeHTML: typeof hutil.unescapeHTML;
+  encodeURL: typeof hutil.encodeURL;
+  decodeURL: typeof hutil.decodeURL;
+  escapeRegExp: typeof hutil.escapeRegExp;
+  stripHTML: typeof hutil.stripHTML;
+  stripIndent: typeof hutil.stripIndent;
+  hash: typeof hutil.hash;
+  createSha1Hash: typeof hutil.createSha1Hash;
+  highlight: typeof hutil.highlight;
+  prismHighlight: typeof hutil.prismHighlight;
+  tocObj: typeof hutil.tocObj;
+  wordWrap: typeof hutil.wordWrap;
+  prettyUrls: typeof hutil.prettyUrls;
+  isExternalLink: typeof hutil.isExternalLink;
+  gravatar: typeof hutil.gravatar;
+  htmlTag: typeof hutil.htmlTag;
+  truncate: typeof hutil.truncate;
+  spawn: typeof hutil.spawn;
+  camelCaseKeys: typeof hutil.camelCaseKeys;
+  deepMerge: typeof hutil.deepMerge;
+}
+
 interface StoreFunction {
-  (...args: any[]): string;
+  (this: HexoContext, ...args: any[]): any;
 }
 
 interface Store {
-  [key: string]: StoreFunction
+  [key: string]: StoreFunction;
 }
 
-
 class Helper {
   public store: Store;
 
diff --git a/lib/extend/processor.ts b/lib/extend/processor.ts
index ce73da1031..f38d3ba1cb 100644
--- a/lib/extend/processor.ts
+++ b/lib/extend/processor.ts
@@ -3,15 +3,15 @@ import { Pattern } from 'hexo-util';
 import type File from '../box/file';
 
 interface StoreFunction {
-  (file: File): any
+  (file: File | string): any;
 }
 
 type Store = {
-    pattern: Pattern;
-    process: StoreFunction
-  }[];
+  pattern: Pattern;
+  process: StoreFunction;
+}[];
 
-type patternType = Exclude<ConstructorParameters<typeof Pattern>[0], ((str: string) => string)>;
+type patternType = Exclude<ConstructorParameters<typeof Pattern>[0], (str: string) => string>;
 class Processor {
   public store: Store;
 
diff --git a/lib/plugins/filter/template_locals/i18n.ts b/lib/plugins/filter/template_locals/i18n.ts
index 87c505280b..7411a94b23 100644
--- a/lib/plugins/filter/template_locals/i18n.ts
+++ b/lib/plugins/filter/template_locals/i18n.ts
@@ -15,7 +15,7 @@ function i18nLocalsFilter(this: Hexo, locals: LocalsType): void {
     const pattern = new Pattern(`${i18nDir}/*path`);
     const data = pattern.match(locals.path);
 
-    if (data && data.lang && i18nLanguages.includes(data.lang)) {
+    if (data && 'lang' in data && i18nLanguages.includes(data.lang)) {
       lang = data.lang;
       page.canonical_path = data.path;
     } else {