diff --git a/src/vs/workbench/api/browser/mainThreadNotebookKernels.ts b/src/vs/workbench/api/browser/mainThreadNotebookKernels.ts
index 86394fdf58d..efc7566861f 100644
--- a/src/vs/workbench/api/browser/mainThreadNotebookKernels.ts
+++ b/src/vs/workbench/api/browser/mainThreadNotebookKernels.ts
@@ -249,4 +249,8 @@ export class MainThreadNotebookKernels implements MainThreadNotebookKernelsShape
 			}
 		});
 	}
+
+	$removeExecution(handle: number): void {
+		this._executions.delete(handle);
+	}
 }
diff --git a/src/vs/workbench/api/common/extHost.protocol.ts b/src/vs/workbench/api/common/extHost.protocol.ts
index 8b93af59d2b..c4cac515b3c 100644
--- a/src/vs/workbench/api/common/extHost.protocol.ts
+++ b/src/vs/workbench/api/common/extHost.protocol.ts
@@ -926,7 +926,15 @@ export interface ICellExecuteOutputItemEditDto {
 	items: NotebookOutputItemDto[]
 }
 
-export type ICellExecuteUpdateDto = ICellExecuteOutputEditDto | ICellExecuteOutputItemEditDto | ICellExecutionStateUpdate | ICellExecutionComplete;
+export interface ICellExecutionStateUpdateDto extends ICellExecutionStateUpdate {
+	executionHandle: number;
+}
+
+export interface ICellExecutionCompleteDto extends ICellExecutionComplete {
+	executionHandle: number;
+}
+
+export type ICellExecuteUpdateDto = ICellExecuteOutputEditDto | ICellExecuteOutputItemEditDto | ICellExecutionStateUpdateDto | ICellExecutionCompleteDto;
 
 export interface MainThreadNotebookKernelsShape extends IDisposable {
 	$postMessage(handle: number, editorId: string | undefined, message: any): Promise<boolean>;
@@ -937,6 +945,7 @@ export interface MainThreadNotebookKernelsShape extends IDisposable {
 
 	$addExecution(handle: number, uri: UriComponents, cellHandle: number): void;
 	$updateExecutions(data: ICellExecuteUpdateDto[]): void;
+	$removeExecution(handle: number): void;
 }
 
 export interface MainThreadNotebookRenderersShape extends IDisposable {
diff --git a/src/vs/workbench/api/common/extHostNotebookKernels.ts b/src/vs/workbench/api/common/extHostNotebookKernels.ts
index 87e0868cc70..c8b57133dba 100644
--- a/src/vs/workbench/api/common/extHostNotebookKernels.ts
+++ b/src/vs/workbench/api/common/extHostNotebookKernels.ts
@@ -472,6 +472,8 @@ class NotebookCellExecutionTask extends Disposable {
 				// The last update needs to be ordered correctly and applied immediately,
 				// so we use updateSoon and immediately flush.
 				that._collector.flush();
+
+				that._proxy.$removeExecution(that._handle);
 			},
 
 			clearOutput(cell?: vscode.NotebookCell): Thenable<void> {
diff --git a/src/vs/workbench/contrib/notebook/browser/notebookExecutionServiceImpl.ts b/src/vs/workbench/contrib/notebook/browser/notebookExecutionServiceImpl.ts
index 8213e7c9826..643eb717044 100644
--- a/src/vs/workbench/contrib/notebook/browser/notebookExecutionServiceImpl.ts
+++ b/src/vs/workbench/contrib/notebook/browser/notebookExecutionServiceImpl.ts
@@ -3,6 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+import { IDisposable } from 'vs/base/common/lifecycle';
 import { URI } from 'vs/base/common/uri';
 import { NotebookTextModel } from 'vs/workbench/contrib/notebook/common/model/notebookTextModel';
 import { CellEditType, ICellEditOperation, NotebookCellExecutionState, NotebookCellInternalMetadata } from 'vs/workbench/contrib/notebook/common/notebookCommon';
@@ -67,9 +68,11 @@ function updateToEdit(update: ICellExecuteUpdate, cellHandle: number): ICellEdit
 	throw new Error('Unknown cell update type');
 }
 
-class CellExecution implements INotebookCellExecution {
+class CellExecution implements INotebookCellExecution, IDisposable {
 	private readonly _notebookModel: NotebookTextModel;
 
+	private _isDisposed = false;
+
 	constructor(
 		readonly notebook: URI,
 		readonly cellHandle: number,
@@ -93,8 +96,20 @@ class CellExecution implements INotebookCellExecution {
 	}
 
 	update(updates: ICellExecuteUpdate[]): void {
+		if (this._isDisposed) {
+			throw new Error('Cannot update disposed execution');
+		}
+
 		const edits = updates.map(update => updateToEdit(update, this.cellHandle));
 		this._applyExecutionEdits(edits);
+
+		if (updates.some(u => u.editType === CellExecutionUpdateType.Complete)) {
+			this.dispose();
+		}
+	}
+
+	dispose(): void {
+		this._isDisposed = true;
 	}
 
 	private _applyExecutionEdits(edits: ICellEditOperation[]): void {
diff --git a/src/vs/workbench/contrib/notebook/common/notebookExecutionService.ts b/src/vs/workbench/contrib/notebook/common/notebookExecutionService.ts
index 7ba8fd9b77a..0f14b023a82 100644
--- a/src/vs/workbench/contrib/notebook/common/notebookExecutionService.ts
+++ b/src/vs/workbench/contrib/notebook/common/notebookExecutionService.ts
@@ -16,7 +16,6 @@ export enum CellExecutionUpdateType {
 
 export interface ICellExecuteOutputEdit {
 	editType: CellExecutionUpdateType.Output;
-	executionHandle: number;
 	cellHandle: number;
 	append?: boolean;
 	outputs: IOutputDto[]
@@ -24,7 +23,6 @@ export interface ICellExecuteOutputEdit {
 
 export interface ICellExecuteOutputItemEdit {
 	editType: CellExecutionUpdateType.OutputItems;
-	executionHandle: number;
 	append?: boolean;
 	outputId: string;
 	items: IOutputItemDto[]
@@ -34,14 +32,12 @@ export type ICellExecuteUpdate = ICellExecuteOutputEdit | ICellExecuteOutputItem
 
 export interface ICellExecutionStateUpdate {
 	editType: CellExecutionUpdateType.ExecutionState;
-	executionHandle: number;
 	executionOrder?: number;
 	runStartTime?: number;
 }
 
 export interface ICellExecutionComplete {
 	editType: CellExecutionUpdateType.Complete;
-	executionHandle: number;
 	runEndTime?: number;
 	lastRunSuccess?: boolean;
 }
@@ -57,6 +53,5 @@ export const INotebookExecutionService = createDecorator<INotebookExecutionServi
 export interface INotebookExecutionService {
 	_serviceBrand: undefined;
 
-	// getExecutions(notebook: URI): INotebookCellExecution[];
 	createNotebookCellExecution(notebook: URI, cellHandle: number): INotebookCellExecution;
 }