diff --git a/addons/notes/package.json b/addons/notes/package.json
index 4168cf6eb6b..0393ba4b6a7 100644
--- a/addons/notes/package.json
+++ b/addons/notes/package.json
@@ -30,6 +30,9 @@
     "@storybook/addons": "4.1.0-alpha.1",
     "marked": "^0.5.1"
   },
+  "devDependencies": {
+    "@types/marked": "^0.4.2"
+  },
   "peerDependencies": {
     "react": "*"
   }
diff --git a/addons/notes/src/addon.ts b/addons/notes/src/addon.ts
index 2ff6bb0d7a5..6adaaf06592 100644
--- a/addons/notes/src/addon.ts
+++ b/addons/notes/src/addon.ts
@@ -1,8 +1,10 @@
 import addons, { makeDecorator } from '@storybook/addons';
-import marked from 'marked';
+import { MarkedOptions, parse as marked } from 'marked';
 
-function renderMarkdown(text, options) {
-  return marked(text, { ...marked.defaults, ...options });
+// todo why not just calling marked directly instead of wrapping it?
+// todo removed { marked.defaults, options } merge. I believe this was not necessary, have to check
+function renderMarkdown(text: string, options?: MarkedOptions) {
+  return marked(text, options);
 }
 
 export const withNotes = makeDecorator({
@@ -39,5 +41,3 @@ export const withMarkdownNotes = (text, options) =>
     markdown: text,
     markdownOptions: options,
   });
-
-export default withNotes;
diff --git a/yarn.lock b/yarn.lock
index 6065946bae3..ae599f25154 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2017,6 +2017,11 @@
   resolved "https://registry.yarnpkg.com/@types/json5/-/json5-0.0.29.tgz#ee28707ae94e11d2b827bcbe5270bcea7f3e71ee"
   integrity sha1-7ihweulOEdK4J7y+UnC86n8+ce4=
 
+"@types/marked@^0.4.2":
+  version "0.4.2"
+  resolved "https://registry.yarnpkg.com/@types/marked/-/marked-0.4.2.tgz#64a89e53ea37f61cc0f3ee1732c555c2dbf6452f"
+  integrity sha512-cDB930/7MbzaGF6U3IwSQp6XBru8xWajF5PV2YZZeV8DyiliTuld11afVztGI9+yJZ29il5E+NpGA6ooV/Cjkg==
+
 "@types/node@*", "@types/node@~10.12.1":
   version "10.12.1"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-10.12.1.tgz#da61b64a2930a80fa708e57c45cd5441eb379d5b"