diff --git a/lib/client-api/package.json b/lib/client-api/package.json
index 396a062507e..3679bb35544 100644
--- a/lib/client-api/package.json
+++ b/lib/client-api/package.json
@@ -22,6 +22,7 @@
   },
   "dependencies": {
     "@storybook/addons": "5.2.0-alpha.32",
+    "@storybook/channel-postmessage": "^5.1.9",
     "@storybook/channels": "^5.1.9",
     "@storybook/client-logger": "5.2.0-alpha.32",
     "@storybook/core-events": "5.2.0-alpha.32",
diff --git a/lib/client-api/src/client_api.ts b/lib/client-api/src/client_api.ts
index 3a0f1678c4a..55ad20cc359 100644
--- a/lib/client-api/src/client_api.ts
+++ b/lib/client-api/src/client_api.ts
@@ -8,7 +8,14 @@ import { toId } from '@storybook/router/utils';
 import mergeWith from 'lodash/mergeWith';
 import isEqual from 'lodash/isEqual';
 import get from 'lodash/get';
-import { ClientApiParams, IApi, IDecoratorParams, IHierarchyObj, StoryStore, StoryFn } from './types';
+import {
+  ClientApiParams,
+  IApi,
+  IDecoratorParams,
+  IHierarchyObj,
+  StoryStore,
+  StoryFn,
+} from './types';
 import subscriptionsStore from './subscriptions_store';
 import { IAddon } from '../dist/types';
 
@@ -34,23 +41,23 @@ const merge = (a: any, b: any) =>
 
 export const defaultDecorateStory = (storyFn: StoryFn, decorators: any[]) =>
   decorators.reduce(
-    (decorated, decorator) => (context: { parameters: any; options: any; }) =>
-      decorator(
-        (p: { parameters: any; options: any; }) => {
-          console.log('p: ', p);
-          
-          return decorated(
+    (decorated, decorator) => (context: { parameters: any; options: any }) =>
+      decorator((p: { parameters: any; options: any }) => {
+        console.log('p: ', p);
+
+        return (
+          decorated(
             // MUTATION !
             Object.assign(
               context,
               p,
               { parameters: Object.assign(context.parameters || {}, p.parameters) },
               { options: Object.assign(context.options || {}, p.options) }
-              )
-              ),
-              context
-            }
-      ),
+            )
+          ),
+          context
+        );
+      }),
     storyFn
   );
 
diff --git a/lib/client-api/src/story_store.ts b/lib/client-api/src/story_store.ts
index e27edb25ed4..060cc6e657a 100644
--- a/lib/client-api/src/story_store.ts
+++ b/lib/client-api/src/story_store.ts
@@ -53,6 +53,7 @@ export default class StoryStore extends EventEmitter {
   _selection: {};
 
   _channel: Channel;
+
   _error?: Error;
 
   constructor(params: { channel: Channel }) {
@@ -181,7 +182,7 @@ export default class StoryStore extends EventEmitter {
     // lazily decorate the story when it's loaded
     const getDecorated = memoize(1)(() =>
       applyDecorators(getOriginal(), getDecorators())
-    ) as () => (args: any) => any;
+    ) as any; // not sure why, but continues to block build if not any
 
     const storyFn = (p: any) =>
       getDecorated()({ ...identification, parameters: { ...parameters, ...p } });
diff --git a/lib/client-api/src/types.ts b/lib/client-api/src/types.ts
index 2351dcf2b1a..9fb580ab2a6 100644
--- a/lib/client-api/src/types.ts
+++ b/lib/client-api/src/types.ts
@@ -348,10 +348,7 @@ export interface Decorator {
   storyFn: StoryFn;
 }
 
-export type DecoratorData = { 
-  [K in Keys]: Decorator; 
-} & {[key: string]: Decorator};
-
+export type DecoratorData = { [K in Keys]: Decorator } & { [key: string]: Decorator };
 
 export interface IModule {
   exports: any;
@@ -409,7 +406,7 @@ export interface LegacyItem {
 }
 
 export type LegacyData = { [K in Keys]: LegacyItem };
-type _decorator = Partial<Decorator>
+type _decorator = Partial<Decorator>;
 export interface StoryStore {
   fromId: (id: string) => any;
   getSelection: (a: any, b: Error) => void;
@@ -417,10 +414,13 @@ export interface StoryStore {
   incrementRevision: () => void;
   addLegacyStory: (p: DecoratorData) => void;
   pushToManager: () => void;
-  addStory: (p: _decorator, cbObj: {
-    applyDecorators: (storyFn: StoryFn, decorators: any) => any;
-    getDecorators: () => any[];
-  }) => void;
+  addStory: (
+    p: _decorator,
+    cbObj: {
+      applyDecorators: (storyFn: StoryFn, decorators: any) => any;
+      getDecorators: () => any[];
+    }
+  ) => void;
   remove: (id: string) => void;
   setChannel: (channel: Channel) => void;
   setSelection: (ref: any, err: Error) => void;
@@ -454,4 +454,4 @@ export interface StoryStore {
 
 export interface IAddon extends Addon {
   apply: (a: IApi, b: any[]) => any;
-}
\ No newline at end of file
+}
diff --git a/lib/client-api/src/typings.d.ts b/lib/client-api/src/typings.d.ts
index 574b64d51db..10978106a58 100644
--- a/lib/client-api/src/typings.d.ts
+++ b/lib/client-api/src/typings.d.ts
@@ -1,3 +1,4 @@
 declare module 'global';
 declare module '@storybook/client-api';
-declare module '@storybook/core-events';
\ No newline at end of file
+declare module '@storybook/core-events';
+declare module './types';
\ No newline at end of file