diff --git a/__tests__/src/actions/window.test.js b/__tests__/src/actions/window.test.js
index ba983c88c09d7677974b24a3b83fe2e69a6bf527..c144d7d2d94b9bdef18563b8e30ba7ccc04fd26c 100644
--- a/__tests__/src/actions/window.test.js
+++ b/__tests__/src/actions/window.test.js
@@ -15,20 +15,24 @@ describe('window actions', () => {
           id: 'helloworld',
           canvasIndex: 1,
           collectionIndex: 0,
-          companionWindowIds: [],
           manifestId: null,
           maximized: false,
           rangeId: null,
           thumbnailNavigationPosition: 'bottom',
           x: 2700,
           y: 2700,
+          sideBarPanel: 'info',
           width: 400,
           height: 400,
           rotation: null,
           view: 'single',
         },
+        companionWindows: [{ position: 'left', content: 'info' }],
       };
-      expect(actions.addWindow(options)).toEqual(expectedAction);
+      const action = actions.addWindow(options);
+      expect(action).toMatchObject(expectedAction);
+      expect(action.window.companionWindowIds.length).toEqual(1);
+      expect(action.window.companionWindowIds[0]).toEqual(action.companionWindows[0].id);
     });
   });
 
diff --git a/__tests__/src/reducers/companionWindows.test.js b/__tests__/src/reducers/companionWindows.test.js
index 68775833910068ef0252fdf95084980790c37c1a..9f33e9ecf64c6c1aa05470a9149c470e913678af 100644
--- a/__tests__/src/reducers/companionWindows.test.js
+++ b/__tests__/src/reducers/companionWindows.test.js
@@ -20,6 +20,22 @@ describe('companionWindowsReducer', () => {
     });
   });
 
+  describe('ADD_WINDOW', () => {
+    it('adds default companion window(s)', () => {
+      const action = {
+        type: ActionTypes.ADD_WINDOW,
+        companionWindows: [{ id: 'banana', position: 'left', content: 'info' }, { id: 'Banane', position: 'right', content: 'canvas_navigation' }],
+      };
+      const beforeState = {};
+      const expectedState = {
+        banana: { id: 'banana', position: 'left', content: 'info' },
+        Banane: { id: 'Banane', position: 'right', content: 'canvas_navigation' },
+      };
+      expect(companionWindowsReducer(beforeState, action)).toEqual(expectedState);
+    });
+  });
+
+
   describe('UPDATE_COMPANION_WINDOW', () => {
     it('updates an existing companion window', () => {
       const action = {