diff --git a/.travis.yml b/.travis.yml
index 09fbd47..b54d6dd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,7 +4,7 @@ python:
   - "3.6"
 
 install:
-  - pip install flake8 jupyterlab~=1.2
+  - pip install flake8 "jupyterlab>=2,<3"
 
 script:
   - pwd
diff --git a/README.md b/README.md
index 8c4bbe9..d96572b 100644
--- a/README.md
+++ b/README.md
@@ -113,3 +113,8 @@ Jupyter Lab:
     jupyter labextension link
 
 Tagged releases of this repository are automatically published to Pypi and NPM by Travis.
+
+To test that the binder and repo buttons work when developing locally set some placeholder environment variables, e.g.:
+```
+BINDER_LAUNCH_HOST=http://localhost BINDER_REPO_URL=http://localhost BINDER_PERSISTENT_REQUEST=v2/gh/repo BINDER_REF_URL=http://localhost jupyter-lab --debug
+```
diff --git a/binder/postBuild b/binder/postBuild
index aad2e0b..2f1294a 100644
--- a/binder/postBuild
+++ b/binder/postBuild
@@ -4,6 +4,13 @@ set -eux
 env | sort
 pwd
 
+# jupyter-offlinenotebook is automatically installed by repo2docker.
+# Uninstall to avoid conflicts
+jupyter labextension uninstall --no-build jupyter-offlinenotebook
+
+# Upgrade jupyterlab if necessary
+conda install jupyterlab=2
+
 # repo2docker copies this repo into $HOME which means jupyter labextension
 # picks up hidden dot files and runs into problems so install from a
 # different directory
diff --git a/jupyter_offlinenotebook/static/jslib/index.ts b/jupyter_offlinenotebook/static/jslib/index.ts
index 8aee82b..dd12ed9 100644
--- a/jupyter_offlinenotebook/static/jslib/index.ts
+++ b/jupyter_offlinenotebook/static/jslib/index.ts
@@ -1,11 +1,11 @@
 import {
   IDisposable,
   DisposableDelegate
-} from '@phosphor/disposable';
+} from '@lumino/disposable';
 
 import {
   Widget
-} from '@phosphor/widgets';
+} from '@lumino/widgets';
 
 import {
   PageConfig
@@ -35,7 +35,13 @@ import {
 import * as offline from "./offlinenotebook";
 
 import $ from "jquery";
-import { JSONValue } from '@phosphor/coreutils';
+import { PartialJSONValue } from '@lumino/coreutils';
+
+
+/**
+ * The CSS class for a Toolbar icon.
+ */
+const CSS_ICON_CLASS = 'jp-OfflineNotebookToolbarIcon';
 
 /**
  * The plugin registration information.
@@ -66,7 +72,7 @@ export
     let buttons: Array<[string, ToolbarButton]> = [];
     buttons.push(['downloadVisible', new ToolbarButton({
       className: 'downloadVisible',
-      iconClassName: 'fa fa-download',
+      iconClass: 'fas fa-download ' + CSS_ICON_CLASS,
       onClick: () => {
         downloadNotebookFromBrowser(panel);
       },
@@ -77,7 +83,7 @@ export
     if (offline.repoid()) {
       buttons.push(['saveToBrowser', new ToolbarButton({
         className: 'saveToBrowser',
-        iconClassName: 'fa fa-cloud-download',
+        iconClass: 'fas fa-cloud-download-alt ' + CSS_ICON_CLASS,
         onClick: () => {
           localstoreSaveNotebook(panel);
         },
@@ -85,7 +91,7 @@ export
       })]);
       buttons.push(['loadFromBrowser', new ToolbarButton({
         className: 'loadFromBrowser',
-        iconClassName: 'fa fa-cloud-upload',
+        iconClass: 'fas fa-cloud-upload-alt ' + CSS_ICON_CLASS,
         onClick: () => {
           localstoreLoadNotebook(panel);
         },
@@ -98,14 +104,14 @@ export
     }
     if (offline.binderRefUrl()) {
       let repoIcons: StringStringMap = {
-        'GitHub': 'fa fa-github',
-        'GitLab': 'fa fa-gitlab',
-        'Git': 'fa fa-git'
+        'GitHub': 'fab fa-github',
+        'GitLab': 'fab fa-gitlab',
+        'Git': 'fab fa-git'
       }
 
       buttons.push(['openRepo', new ToolbarButton({
         className: 'openRepo',
-        iconClassName: repoIcons[offline.repoLabel()] || 'fa-external-link',
+        iconClass: (repoIcons[offline.repoLabel()] || 'fas fa-external-link-alt') + ' ' + CSS_ICON_CLASS,
         onClick: offline.openBinderRepo,
         tooltip: 'Visit Binder repository',
         label: offline.repoLabel()
@@ -114,7 +120,7 @@ export
     if (offline.binderPersistentUrl()) {
       buttons.push(['linkToBinder', new ToolbarButton({
         className: 'linkToBinder',
-        iconClassName: 'fa fa-link',
+        iconClass: 'fas fa-link ' + CSS_ICON_CLASS,
         onClick: () => {
           showBinderLink(panel);
         },
@@ -145,7 +151,12 @@ function formatRepoPathforDialog(path: string): string {
 
 function localstoreSaveNotebook(panel: NotebookPanel) {
   var path = panel.context.path;
-  var nb = panel.content.model.toJSON()
+  var nb = panel.content.model?.toJSON();
+  if (!nb) {
+    var e = 'Content model is null';
+    showErrorMessage('Local storage error', e);
+    throw (e);
+  }
   var repopathDisplay = formatRepoPathforDialog(path);
   offline.saveNotebook(path, nb,
     function (key: string) {
@@ -176,7 +187,7 @@ function localstoreLoadNotebook(panel: NotebookPanel) {
   var repopathDisplay = formatRepoPathforDialog(path);
   var key = 'repoid:' + offline.repoid() + ' path:' + path;
   offline.loadNotebook(path,
-    (nb: JSONValue) => {
+    (nb: PartialJSONValue) => {
       if (nb) {
         console.log('offline-notebook found ' + key);
         return showDialog({
@@ -210,7 +221,12 @@ function localstoreLoadNotebook(panel: NotebookPanel) {
 
 function downloadNotebookFromBrowser(panel: NotebookPanel) {
   var name = panel.context.path.replace(/.*\//, '');
-  var nb = panel.content.model.toJSON()
+  var nb = panel.content.model?.toJSON();
+  if (!nb) {
+    var e = 'Content model is null';
+    showErrorMessage('Local storage error', e);
+    throw (e);
+  }
   offline.downloadNotebookFromBrowser(name, nb);
 }
 
@@ -248,7 +264,7 @@ function createCopyShareURLNode(binderUrl: string): HTMLElement {
   })
   button.append(
     $('<i/>', {
-      'class': 'fa fa-clipboard'
+      'class': 'fas fa-clipboard'
     }));
   body.append(button);
   // Unwrap JQuery object
diff --git a/jupyter_offlinenotebook/static/jslib/offlinenotebook.d.ts b/jupyter_offlinenotebook/static/jslib/offlinenotebook.d.ts
index aae62fa..2f2482f 100644
--- a/jupyter_offlinenotebook/static/jslib/offlinenotebook.d.ts
+++ b/jupyter_offlinenotebook/static/jslib/offlinenotebook.d.ts
@@ -1,9 +1,9 @@
-import { JSONValue } from "@phosphor/coreutils";
+import { PartialJSONValue } from "@lumino/coreutils";
 
 export function initialise(data: JSON): null;
-export function saveNotebook(path: string, nb: JSONValue, success: CallableFunction, error: CallableFunction)
+export function saveNotebook(path: string, nb: PartialJSONValue, success: CallableFunction, error: CallableFunction)
 export function loadNotebook(path: string, success: CallableFunction, error: CallableFunction)
-export function downloadNotebookFromBrowser(name: string, nb: JSONValue): null;
+export function downloadNotebookFromBrowser(name: string, nb: PartialJSONValue): null;
 export function openBinderRepo(): null;
 
 export function repoid(): string;
diff --git a/jupyter_offlinenotebook/static/style/index.css b/jupyter_offlinenotebook/static/style/index.css
index e69de29..a6cf7c4 100644
--- a/jupyter_offlinenotebook/static/style/index.css
+++ b/jupyter_offlinenotebook/static/style/index.css
@@ -0,0 +1,7 @@
+/* Toolbar FontAwesome icons
+ * Need to override 'color: unset !important':
+ * https://github.com/jupyterlab/jupyterlab/blob/v2.0.1/packages/ui-components/style/base.css#L70-L73
+ */
+.jp-OfflineNotebookToolbarIcon {
+  color: var(--md-grey-700);
+}
diff --git a/package.json b/package.json
index 0aa666c..dbf88c2 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "jupyter-offlinenotebook",
-  "version": "0.0.11",
+  "version": "0.1.0",
   "description": "JupyterLab offline-notebook extension.",
   "keywords": [
     "jupyter",
@@ -32,17 +32,17 @@
     "watch": "tsc -w"
   },
   "dependencies": {
-    "@jupyterlab/application": "^1.2.1",
-    "@jupyterlab/apputils": "^1.2.1",
-    "@jupyterlab/docregistry": "^1.2.1",
-    "@jupyterlab/notebook": "^1.2.2",
-    "@phosphor/disposable": "^1.3.1",
+    "@jupyterlab/application": "^2.0.2",
+    "@jupyterlab/apputils": "^2.0.2",
+    "@jupyterlab/docregistry": "^2.0.2",
+    "@jupyterlab/notebook": "^2.0.2",
+    "@lumino/disposable": "^1.3.5",
     "@types/jquery": "^3",
     "jquery": "^3"
   },
   "devDependencies": {
     "rimraf": "~3.0.0",
-    "typescript": "~3.7.2"
+    "typescript": "~3.7.3"
   },
   "sideEffects": [
     "jupyter_offlinenotebook/static/style/*.css"