diff --git a/packages/application-extension/src/index.ts b/packages/application-extension/src/index.ts
index 9ccbe5d01..afc73161c 100644
--- a/packages/application-extension/src/index.ts
+++ b/packages/application-extension/src/index.ts
@@ -28,8 +28,6 @@ import { DocumentWidget } from '@jupyterlab/docregistry';
 
 import { IMainMenu } from '@jupyterlab/mainmenu';
 
-import { INotebookTools } from '@jupyterlab/notebook';
-
 import { ISettingRegistry } from '@jupyterlab/settingregistry';
 
 import { ITranslator } from '@jupyterlab/translation';
@@ -603,15 +601,14 @@ const topVisibility: JupyterFrontEndPlugin<void> = {
 const sidebarVisibility: JupyterFrontEndPlugin<void> = {
   id: '@jupyter-notebook/application-extension:sidebar',
   requires: [INotebookShell, ITranslator],
-  optional: [IMainMenu, ICommandPalette, INotebookTools],
+  optional: [IMainMenu, ICommandPalette],
   autoStart: true,
   activate: (
     app: JupyterFrontEnd<JupyterFrontEnd.IShell>,
     notebookShell: INotebookShell,
     translator: ITranslator,
     menu: IMainMenu | null,
-    palette: ICommandPalette | null,
-    notebookTools: INotebookTools | null
+    palette: ICommandPalette | null
   ) => {
     if (!sidePanelsEnabled()) {
       return;
@@ -619,7 +616,7 @@ const sidebarVisibility: JupyterFrontEndPlugin<void> = {
 
     const trans = translator.load('notebook');
 
-    var sideBarMenu: SideBarPanel.sideBarMenu = {
+    const sideBarMenu: SideBarPanel.sideBarMenu = {
       left: null,
       right: null
     };
diff --git a/packages/application/src/shell.ts b/packages/application/src/shell.ts
index b9477ec7b..d97f03f8a 100644
--- a/packages/application/src/shell.ts
+++ b/packages/application/src/shell.ts
@@ -3,7 +3,7 @@
 
 import { JupyterFrontEnd } from '@jupyterlab/application';
 import { DocumentRegistry } from '@jupyterlab/docregistry';
-import { closeIcon, LabIcon, ReactWidget } from '@jupyterlab/ui-components';
+import { closeIcon } from '@jupyterlab/ui-components';
 
 import { ArrayExt, find } from '@lumino/algorithm';
 import { PromiseDelegate, Token } from '@lumino/coreutils';
@@ -19,7 +19,6 @@ import {
   StackedPanel,
   Widget
 } from '@lumino/widgets';
-import React from 'react';
 
 /**
  * The Jupyter Notebook application shell token.
@@ -420,22 +419,19 @@ export class SideBarHandler {
     this._widgetPanel = new StackedPanel();
     this._widgetPanel.widgetRemoved.connect(this._onWidgetRemoved, this);
 
-    const that = this;
-    const collapseIcon = React.createElement(
-      'div',
-      {
-        onClick: () => {
-          that.collapse();
-          that.hide();
-        }
-      },
-      LabIcon.resolveReact({
-        icon: closeIcon,
-        className: 'jp-SidePanel-collapse'
-      })
-    );
-
-    this._panel.addWidget(ReactWidget.create(collapseIcon));
+    const closeButton = document.createElement('button');
+    closeIcon.element({
+      container: closeButton,
+      height: '16px',
+      width: 'auto'
+    });
+    closeButton.onclick = () => {
+      this.collapse();
+      this.hide();
+    };
+    closeButton.className = 'jp-Button jp-SidePanel-collapse';
+    const icon = new Widget({ node: closeButton });
+    this._panel.addWidget(icon);
     this._panel.addWidget(this._widgetPanel);
   }
 
diff --git a/packages/application/style/sidepanel.css b/packages/application/style/sidepanel.css
index cb8f7058c..8acb70766 100644
--- a/packages/application/style/sidepanel.css
+++ b/packages/application/style/sidepanel.css
@@ -17,10 +17,6 @@
 | SideBar
 |----------------------------------------------------------------------------*/
 
-/* Left */
-
-/* Right */
-
 /* Stack panels */
 
 #jp-right-stack,
@@ -30,14 +26,6 @@
   min-width: var(--jp-sidebar-min-width);
 }
 
-#jp-right-stack {
-  border-left: var(--jp-border-width) solid var(--jp-border-color1);
-}
-
-#jp-left-stack {
-  border-right: var(--jp-border-width) solid var(--jp-border-color1);
-}
-
 #jp-left-stack .jp-SidePanel-collapse,
 #jp-right-stack .jp-SidePanel-collapse {
   display: flex;
@@ -48,6 +36,10 @@
   justify-content: right;
 }
 
+#jp-right-stack .jp-SidePanel-collapse {
+  justify-content: left;
+}
+
 #jp-left-stack .lm-StackedPanel,
 #jp-right-stack .lm-StackedPanel {
   flex: 1 1 auto;
diff --git a/packages/notebook-extension/src/index.ts b/packages/notebook-extension/src/index.ts
index ae42471ae..22b7597c0 100644
--- a/packages/notebook-extension/src/index.ts
+++ b/packages/notebook-extension/src/index.ts
@@ -337,8 +337,7 @@ const scrollOutput: JupyterFrontEndPlugin<void> = {
 const notebookToolsWidget: JupyterFrontEndPlugin<void> = {
   id: '@jupyter-notebook/notebook-extension:notebook-tools',
   autoStart: true,
-  requires: [INotebookShell],
-  optional: [INotebookTools],
+  requires: [INotebookShell, INotebookTools],
   activate: (
     app: JupyterFrontEnd,
     shell: INotebookShell,