diff --git a/src/tsconfig.strictNullChecks.json b/src/tsconfig.strictNullChecks.json
index 39b83a76bfa..a02eaeb4b2d 100644
--- a/src/tsconfig.strictNullChecks.json
+++ b/src/tsconfig.strictNullChecks.json
@@ -104,6 +104,7 @@
 		"./vs/base/node/request.ts",
 		"./vs/base/parts/contextmenu/common/contextmenu.ts",
 		"./vs/base/parts/contextmenu/electron-main/contextmenu.ts",
+		"./vs/base/parts/ipc/node/ipc.ts",
 		"./vs/base/parts/quickopen/common/quickOpen.ts",
 		"./vs/base/test/common/utils.ts",
 		"./vs/base/test/node/uri.test.perf.ts",
@@ -371,6 +372,7 @@
 		"./vs/platform/environment/common/environment.ts",
 		"./vs/platform/extensionManagement/common/extensionManagement.ts",
 		"./vs/platform/extensionManagement/common/extensionNls.ts",
+		"./vs/platform/extensionManagement/node/extensionManagementIpc.ts",
 		"./vs/platform/extensions/common/extensionHost.ts",
 		"./vs/platform/extensions/common/extensions.ts",
 		"./vs/platform/extensions/node/extensionValidator.ts",
@@ -508,6 +510,7 @@
 		"./vs/workbench/services/keybinding/common/macLinuxKeyboardMapper.ts",
 		"./vs/workbench/services/keybinding/common/windowsKeyboardMapper.ts",
 		"./vs/workbench/services/mode/common/workbenchModeService.ts",
+
 		"./vs/workbench/services/panel/common/panelService.ts",
 		"./vs/workbench/services/progress/common/progress.ts",
 		"./vs/workbench/services/scm/common/scm.ts",
diff --git a/src/vs/platform/extensionManagement/node/extensionManagementIpc.ts b/src/vs/platform/extensionManagement/node/extensionManagementIpc.ts
index 43931e9a68c..0bce6d8d03c 100644
--- a/src/vs/platform/extensionManagement/node/extensionManagementIpc.ts
+++ b/src/vs/platform/extensionManagement/node/extensionManagementIpc.ts
@@ -21,7 +21,7 @@ export interface IExtensionManagementChannel extends IChannel {
 	call(command: 'installFromGallery', args: [IGalleryExtension]): Thenable<void>;
 	call(command: 'uninstall', args: [ILocalExtension, boolean]): Thenable<void>;
 	call(command: 'reinstallFromGallery', args: [ILocalExtension]): Thenable<void>;
-	call(command: 'getInstalled', args: [LocalExtensionType]): Thenable<ILocalExtension[]>;
+	call(command: 'getInstalled', args: [LocalExtensionType | null]): Thenable<ILocalExtension[]>;
 	call(command: 'getExtensionsReport'): Thenable<IReportedExtension[]>;
 	call(command: 'updateMetadata', args: [ILocalExtension, IGalleryMetadata]): Thenable<ILocalExtension>;
 }
@@ -100,7 +100,7 @@ export class ExtensionManagementChannelClient implements IExtensionManagementSer
 	}
 
 	uninstall(extension: ILocalExtension, force = false): Promise<void> {
-		return Promise.resolve(this.channel.call('uninstall', [this._transformOutgoing(extension), force]));
+		return Promise.resolve(this.channel.call('uninstall', [this._transformOutgoing(extension)!, force]));
 	}
 
 	reinstallFromGallery(extension: ILocalExtension): Promise<void> {
@@ -121,11 +121,15 @@ export class ExtensionManagementChannelClient implements IExtensionManagementSer
 		return Promise.resolve(this.channel.call('getExtensionsReport'));
 	}
 
-	private _transformIncoming(extension: ILocalExtension): ILocalExtension {
+	private _transformIncoming(extension: ILocalExtension): ILocalExtension;
+	private _transformIncoming(extension: ILocalExtension | undefined): ILocalExtension | undefined;
+	private _transformIncoming(extension: ILocalExtension | undefined): ILocalExtension | undefined {
 		return extension ? { ...extension, ...{ location: URI.revive(this.uriTransformer.transformIncoming(extension.location)) } } : extension;
 	}
 
-	private _transformOutgoing(extension: ILocalExtension): ILocalExtension {
+	private _transformOutgoing(extension: ILocalExtension): ILocalExtension;
+	private _transformOutgoing(extension: ILocalExtension | undefined): ILocalExtension | undefined;
+	private _transformOutgoing(extension: ILocalExtension | undefined): ILocalExtension | undefined {
 		return extension ? { ...extension, ...{ location: this.uriTransformer.transformOutgoing(extension.location) } } : extension;
 	}