diff --git a/src/vs/workbench/api/browser/mainThreadNotebook.ts b/src/vs/workbench/api/browser/mainThreadNotebook.ts
index a2aac4fd668..ea6205a7970 100644
--- a/src/vs/workbench/api/browser/mainThreadNotebook.ts
+++ b/src/vs/workbench/api/browser/mainThreadNotebook.ts
@@ -9,7 +9,7 @@ import { Disposable, IDisposable } from 'vs/base/common/lifecycle';
 import { URI, UriComponents } from 'vs/base/common/uri';
 import { INotebookService, IMainNotebookController } from 'vs/workbench/contrib/notebook/browser/notebookService';
 import { Emitter, Event } from 'vs/base/common/event';
-import { ICell, IOutput, INotebook, INotebookMimeTypeSelector, NOTEBOOK_DISPLAY_ORDER, NotebookCellsSplice, NotebookCellOutputsSplice } from 'vs/workbench/contrib/notebook/common/notebookCommon';
+import { ICell, IOutput, INotebook, INotebookMimeTypeSelector, NOTEBOOK_DISPLAY_ORDER, NotebookCellsSplice, NotebookCellOutputsSplice, generateCellPath } from 'vs/workbench/contrib/notebook/common/notebookCommon';
 import { IConfigurationService } from 'vs/platform/configuration/common/configuration';
 
 export class MainThreadCell implements ICell {
@@ -50,7 +50,7 @@ export class MainThreadCell implements ICell {
 		this.uri = URI.from({
 			scheme: 'vscode-notebook',
 			authority: parent.viewType,
-			path: `/cell_${handle}.${cell_type === 'markdown' ? 'md' : 'py'}`,
+			path: generateCellPath(cell_type, handle),
 			query: parent.uri.toString()
 		});
 	}
diff --git a/src/vs/workbench/api/common/extHostNotebook.ts b/src/vs/workbench/api/common/extHostNotebook.ts
index f8a363d5683..aef4c723839 100644
--- a/src/vs/workbench/api/common/extHostNotebook.ts
+++ b/src/vs/workbench/api/common/extHostNotebook.ts
@@ -151,7 +151,7 @@ export class ExtHostCell implements vscode.NotebookCell {
 }
 
 
-export class ExtHostNotebookDocument implements vscode.NotebookDocument {
+export class ExtHostNotebookDocument implements vscode.NotebookDocument, vscode.Disposable {
 	private static _handlePool: number = 0;
 	readonly handle = ExtHostNotebookDocument._handlePool++;
 
@@ -221,6 +221,9 @@ export class ExtHostNotebookDocument implements vscode.NotebookDocument {
 	) {
 
 	}
+	dispose() {
+		this._cellDisposableMapping.forEach(cell => cell.dispose());
+	}
 
 	get fileName() { return this.uri.fsPath; }
 
@@ -425,8 +428,9 @@ export class ExtHostNotebookDocument implements vscode.NotebookDocument {
 	}
 }
 
-export class ExtHostNotebookEditor implements vscode.NotebookEditor {
+export class ExtHostNotebookEditor implements vscode.NotebookEditor, vscode.Disposable {
 	private _viewColumn: vscode.ViewColumn | undefined;
+	private _disposableStore = new DisposableStore();
 
 	constructor(
 		viewType: string,
@@ -435,7 +439,7 @@ export class ExtHostNotebookEditor implements vscode.NotebookEditor {
 		public document: ExtHostNotebookDocument,
 		private _documentsAndEditors: ExtHostDocumentsAndEditors
 	) {
-		this._documentsAndEditors.onDidAddDocuments(documents => {
+		this._disposableStore.add(this._documentsAndEditors.onDidAddDocuments(documents => {
 			for (const data of documents) {
 				let textDocument = data.document;
 				let parsedCellUri = parseCellUri(textDocument.uri);
@@ -455,9 +459,9 @@ export class ExtHostNotebookEditor implements vscode.NotebookEditor {
 					}
 				}
 			}
-		});
+		}));
 
-		this._documentsAndEditors.onDidRemoveDocuments(documents => {
+		this._disposableStore.add(this._documentsAndEditors.onDidRemoveDocuments(documents => {
 			for (const data of documents) {
 				let textDocument = data.document;
 				let parsedCellUri = parseCellUri(textDocument.uri);
@@ -477,7 +481,11 @@ export class ExtHostNotebookEditor implements vscode.NotebookEditor {
 					}
 				}
 			}
-		});
+		}));
+	}
+
+	dispose() {
+		this._disposableStore.dispose();
 	}
 
 	createCell(content: string, language: string, type: 'markdown' | 'code', outputs: vscode.CellOutput[]): vscode.NotebookCell {
@@ -739,12 +747,14 @@ export class ExtHostNotebookController implements ExtHostNotebookShape, ExtHostN
 			let document = this._documents.get(URI.revive(uri).toString());
 
 			if (document) {
+				document.dispose();
 				this._documents.delete(URI.revive(uri).toString());
 			}
 
 			let editor = this._editors.get(URI.revive(uri).toString());
 
 			if (editor) {
+				editor.dispose();
 				this._editors.delete(URI.revive(uri).toString());
 			}
 
diff --git a/src/vs/workbench/contrib/notebook/browser/renderers/cellViewModel.ts b/src/vs/workbench/contrib/notebook/browser/renderers/cellViewModel.ts
index b8f708b97da..2e56f77d475 100644
--- a/src/vs/workbench/contrib/notebook/browser/renderers/cellViewModel.ts
+++ b/src/vs/workbench/contrib/notebook/browser/renderers/cellViewModel.ts
@@ -126,7 +126,7 @@ export class CellViewModel extends Disposable {
 		this._html = null;
 	}
 	save() {
-		if (this._textModel && (this.cell.isDirty || this.isEditing)) {
+		if (this._textModel && !this._textModel.isDisposed() && (this.cell.isDirty || this.isEditing)) {
 			let cnt = this._textModel.getLineCount();
 			this.cell.source = this._textModel.getLinesContent().map((str, index) => str + (index !== cnt - 1 ? '\n' : ''));
 		}