diff --git a/src/shared/versions/release-notes.js b/src/shared/versions/release-notes.js
index 9bd17a2..6ef2335 100644
--- a/src/shared/versions/release-notes.js
+++ b/src/shared/versions/release-notes.js
@@ -1,5 +1,8 @@
 const url = (version) => {
-  return 'https://github.com/ueokande/vim-vixen/releases/tag/' + version;
+  if (version) {
+    return 'https://github.com/ueokande/vim-vixen/releases/tag/' + version;
+  }
+  return 'https://github.com/ueokande/vim-vixen/releases/';
 };
 
 export { url };