diff --git a/lib/output/markdown_ast.js b/lib/output/markdown_ast.js
index a4dfb09a9..c40132703 100644
--- a/lib/output/markdown_ast.js
+++ b/lib/output/markdown_ast.js
@@ -126,7 +126,7 @@ function commentsToAST(comments, opts, callback) {
     }
 
     function githubLink(comment) {
-      return comment.context.github && u('paragraph', [
+      return comment.context && comment.context.github && u('paragraph', [
         u('link', {
           title: 'Source code on GitHub',
           url: comment.context.github