diff --git a/lib/plugins/tag/post_link.ts b/lib/plugins/tag/post_link.ts
index 4460cef8fe..782714a1d2 100644
--- a/lib/plugins/tag/post_link.ts
+++ b/lib/plugins/tag/post_link.ts
@@ -27,9 +27,9 @@ export = ctx => {
       throw new Error(`Post not found: post_link ${slug}.`);
     }
 
-    let title = args.length ? args.join(' ') : post.title;
+    let title = args.length ? args.join(' ') : post.title || post.slug;
     // Let attribute be the true post title so it appears in tooltip.
-    const attrTitle = escapeHTML(post.title);
+    const attrTitle = escapeHTML(post.title || post.slug);
     if (escape === 'true') title = escapeHTML(title);
 
     const link = encodeURL(new URL(post.path, ctx.config.url).pathname);
diff --git a/test/scripts/tags/post_link.js b/test/scripts/tags/post_link.js
index d476933d0a..999f2cad48 100644
--- a/test/scripts/tags/post_link.js
+++ b/test/scripts/tags/post_link.js
@@ -22,6 +22,11 @@ describe('post_link', () => {
     source: 'fôo',
     slug: 'fôo',
     title: 'Hello world'
+  },
+  {
+    source: 'no-title',
+    slug: 'no-title',
+    title: ''
   }])));
 
   it('default', () => {
@@ -36,6 +41,10 @@ describe('post_link', () => {
     postLink(['foo', 'test']).should.eql('<a href="/foo/" title="Hello world">test</a>');
   });
 
+  it('no title', () => {
+    postLink(['no-title']).should.eql('<a href="/no-title/" title="no-title">no-title</a>');
+  });
+
   it('should escape tag in title by default', () => {
     postLink(['title-with-tag']).should.eql('<a href="/title-with-tag/" title="&quot;Hello&quot; &lt;new world&gt;!">&quot;Hello&quot; &lt;new world&gt;!</a>');
   });