diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index fe7977bff96..5a875cb6019 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -60,7 +60,7 @@ export interface IEnvironment {
 export interface IStaticWorkspaceData {
 	id: string;
 	name: string;
-	configuration?: UriComponents;
+	configuration?: UriComponents | null;
 }
 
 export interface IWorkspaceData extends IStaticWorkspaceData {
@@ -71,7 +71,7 @@ export interface IInitData {
 	commit?: string;
 	parentPid: number;
 	environment: IEnvironment;
-	workspace?: IStaticWorkspaceData;
+	workspace?: IStaticWorkspaceData | null;
 	resolvedExtensions: ExtensionIdentifier[];
 	hostExtensions: ExtensionIdentifier[];
 	extensions: IExtensionDescription[];
diff --git a/src/vs/workbench/services/extensions/electron-browser/extensionHost.ts b/src/vs/workbench/services/extensions/electron-browser/extensionHost.ts
index dc7e4284ddc..b04e32cb218 100644
--- a/src/vs/workbench/services/extensions/electron-browser/extensionHost.ts
+++ b/src/vs/workbench/services/extensions/electron-browser/extensionHost.ts
@@ -38,9 +38,9 @@ import { IExtensionDescription } from 'vs/workbench/services/extensions/common/e
 import { withNullAsUndefined } from 'vs/base/common/types';
 
 export interface IExtensionHostStarter {
-	readonly onCrashed: Event<[number, string]>;
+	readonly onCrashed: Event<[number, string | null]>;
 	start(): Promise<IMessagePassingProtocol> | null;
-	getInspectPort(): number;
+	getInspectPort(): number | undefined;
 	dispose(): void;
 }
 
diff --git a/src/vs/workbench/services/extensions/electron-browser/extensionHostProcessManager.ts b/src/vs/workbench/services/extensions/electron-browser/extensionHostProcessManager.ts
index aa60ce0f1f2..bb7cb6dbdff 100644
--- a/src/vs/workbench/services/extensions/electron-browser/extensionHostProcessManager.ts
+++ b/src/vs/workbench/services/extensions/electron-browser/extensionHostProcessManager.ts
@@ -36,7 +36,7 @@ const NO_OP_VOID_PROMISE = Promise.resolve<void>(undefined);
 
 export class ExtensionHostProcessManager extends Disposable {
 
-	public readonly onDidCrash: Event<[number, string]>;
+	public readonly onDidCrash: Event<[number, string | null]>;
 
 	private readonly _onDidChangeResponsiveState: Emitter<ResponsiveState> = this._register(new Emitter<ResponsiveState>());
 	public readonly onDidChangeResponsiveState: Event<ResponsiveState> = this._onDidChangeResponsiveState.event;
diff --git a/src/vs/workbench/services/extensions/electron-browser/extensionService.ts b/src/vs/workbench/services/extensions/electron-browser/extensionService.ts
index 3f2be8776f7..51353982915 100644
--- a/src/vs/workbench/services/extensions/electron-browser/extensionService.ts
+++ b/src/vs/workbench/services/extensions/electron-browser/extensionService.ts
@@ -436,7 +436,7 @@ export class ExtensionService extends Disposable implements IExtensionService {
 		this._extensionHostProcessManagers.push(extHostProcessManager);
 	}
 
-	private _onExtensionHostCrashed(code: number, signal: string): void {
+	private _onExtensionHostCrashed(code: number, signal: string | null): void {
 		console.error('Extension host terminated unexpectedly. Code: ', code, ' Signal: ', signal);
 		this._stopExtensionHostProcess();
 
diff --git a/src/vs/workbench/services/extensions/node/extensionPoints.ts b/src/vs/workbench/services/extensions/node/extensionPoints.ts
index e2b2719a810..5c218653e70 100644
--- a/src/vs/workbench/services/extensions/node/extensionPoints.ts
+++ b/src/vs/workbench/services/extensions/node/extensionPoints.ts
@@ -447,7 +447,7 @@ export class ExtensionScannerInput {
 
 	constructor(
 		public readonly ourVersion: string,
-		public readonly commit: string | undefined,
+		public readonly commit: string | null | undefined,
 		public readonly locale: string | undefined,
 		public readonly devMode: boolean,
 		public readonly absoluteFolderPath: string,