diff --git a/lib/platform/github/index.js b/lib/platform/github/index.js
index 285281cc53737366733940ad402103d84f5f6e7a..9471952ce2db933a2d33e49bb421d9f22d3dbc90 100644
--- a/lib/platform/github/index.js
+++ b/lib/platform/github/index.js
@@ -535,21 +535,30 @@ async function getComments(issueNo) {
 
 async function addComment(issueNo, body) {
   // POST /repos/:owner/:repo/issues/:number/comments
-  await get.post(`repos/${config.repoName}/issues/${issueNo}/comments`, {
-    body: { body },
-  });
+  await get.post(
+    `repos/${config.parentRepo || config.repoName}/issues/${issueNo}/comments`,
+    {
+      body: { body },
+    }
+  );
 }
 
 async function editComment(commentId, body) {
   // PATCH /repos/:owner/:repo/issues/comments/:id
-  await get.patch(`repos/${config.repoName}/issues/comments/${commentId}`, {
-    body: { body },
-  });
+  await get.patch(
+    `repos/${config.parentRepo ||
+      config.repoName}/issues/comments/${commentId}`,
+    {
+      body: { body },
+    }
+  );
 }
 
 async function deleteComment(commentId) {
   // DELETE /repos/:owner/:repo/issues/comments/:id
-  await get.delete(`repos/${config.repoName}/issues/comments/${commentId}`);
+  await get.delete(
+    `repos/${config.parentRepo || config.repoName}/issues/comments/${commentId}`
+  );
 }
 
 async function ensureComment(issueNo, topic, content) {