diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index 48751f1aa75fef5de0f34895779c7a62288bf0b5..4161f1d75c6d705928077d086039faf11ccebc38 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -452,7 +452,7 @@ export interface ExtHostDocumentsShape {
 }
 
 export interface ExtHostDocumentSaveParticipantShape {
-	$participateInSave(resource: URI, reason: SaveReason): Thenable<boolean[]>;
+	$participateInSave(resource: UriComponents, reason: SaveReason): Thenable<boolean[]>;
 }
 
 export interface ITextEditorAddData {
@@ -510,9 +510,9 @@ export interface ExtHostExtensionServiceShape {
 }
 
 export interface FileSystemEvents {
-	created: URI[];
-	changed: URI[];
-	deleted: URI[];
+	created: UriComponents[];
+	changed: UriComponents[];
+	deleted: UriComponents[];
 }
 export interface ExtHostFileSystemEventServiceShape {
 	$onFileEvent(events: FileSystemEvents): void;
@@ -686,7 +686,7 @@ export const MainContext = {
 	MainThreadStorage: createMainId<MainThreadStorageShape>('MainThreadStorage'),
 	MainThreadTelemetry: createMainId<MainThreadTelemetryShape>('MainThreadTelemetry'),
 	MainThreadTerminalService: createMainId<MainThreadTerminalServiceShape>('MainThreadTerminalService'),
-	MainThreadWorkspace: createMainId<MainThreadWorkspaceShape>('MainThreadWorkspace'),
+	MainThreadWorkspace: createMainId<MainThreadWorkspaceShape>('MainThreadWorkspace', ProxyType.CustomMarshaller),
 	MainThreadFileSystem: createMainId<MainThreadFileSystemShape>('MainThreadFileSystem'),
 	MainThreadExtensionService: createMainId<MainThreadExtensionServiceShape>('MainThreadExtensionService'),
 	MainThreadSCM: createMainId<MainThreadSCMShape>('MainThreadSCM', ProxyType.CustomMarshaller),
@@ -703,11 +703,11 @@ export const ExtHostContext = {
 	ExtHostDocumentsAndEditors: createExtId<ExtHostDocumentsAndEditorsShape>('ExtHostDocumentsAndEditors', ProxyType.CustomMarshaller),
 	ExtHostDocuments: createExtId<ExtHostDocumentsShape>('ExtHostDocuments'),
 	ExtHostDocumentContentProviders: createExtId<ExtHostDocumentContentProvidersShape>('ExtHostDocumentContentProviders'),
-	ExtHostDocumentSaveParticipant: createExtId<ExtHostDocumentSaveParticipantShape>('ExtHostDocumentSaveParticipant', ProxyType.CustomMarshaller),
+	ExtHostDocumentSaveParticipant: createExtId<ExtHostDocumentSaveParticipantShape>('ExtHostDocumentSaveParticipant'),
 	ExtHostEditors: createExtId<ExtHostEditorsShape>('ExtHostEditors', ProxyType.CustomMarshaller),
 	ExtHostTreeViews: createExtId<ExtHostTreeViewsShape>('ExtHostTreeViews'),
 	ExtHostFileSystem: createExtId<ExtHostFileSystemShape>('ExtHostFileSystem', ProxyType.CustomMarshaller),
-	ExtHostFileSystemEventService: createExtId<ExtHostFileSystemEventServiceShape>('ExtHostFileSystemEventService', ProxyType.CustomMarshaller),
+	ExtHostFileSystemEventService: createExtId<ExtHostFileSystemEventServiceShape>('ExtHostFileSystemEventService'),
 	ExtHostHeapService: createExtId<ExtHostHeapServiceShape>('ExtHostHeapMonitor'),
 	ExtHostLanguageFeatures: createExtId<ExtHostLanguageFeaturesShape>('ExtHostLanguageFeatures', ProxyType.CustomMarshaller),
 	ExtHostQuickOpen: createExtId<ExtHostQuickOpenShape>('ExtHostQuickOpen'),
diff --git a/src/vs/workbench/api/node/extHostDocumentSaveParticipant.ts b/src/vs/workbench/api/node/extHostDocumentSaveParticipant.ts
index 80b9ae90671d51c3153ba1b49427a364a80af19c..3733a20adbc49e9da144d928817be219ef62cd09 100644
--- a/src/vs/workbench/api/node/extHostDocumentSaveParticipant.ts
+++ b/src/vs/workbench/api/node/extHostDocumentSaveParticipant.ts
@@ -5,7 +5,7 @@
 'use strict';
 
 import Event from 'vs/base/common/event';
-import URI from 'vs/base/common/uri';
+import URI, { UriComponents } from 'vs/base/common/uri';
 import { sequence, always } from 'vs/base/common/async';
 import { illegalState } from 'vs/base/common/errors';
 import { ExtHostDocumentSaveParticipantShape, MainThreadEditorsShape, IWorkspaceResourceEdit } from 'vs/workbench/api/node/extHost.protocol';
@@ -49,7 +49,8 @@ export class ExtHostDocumentSaveParticipant implements ExtHostDocumentSavePartic
 		};
 	}
 
-	$participateInSave(resource: URI, reason: SaveReason): Thenable<boolean[]> {
+	$participateInSave(data: UriComponents, reason: SaveReason): Thenable<boolean[]> {
+		const resource = URI.revive(data);
 		const entries = this._callbacks.toArray();
 
 		let didTimeout = false;
diff --git a/src/vs/workbench/api/node/extHostFileSystemEventService.ts b/src/vs/workbench/api/node/extHostFileSystemEventService.ts
index 1c5aa2b1e289122972576fbb57470b480d970151..1ac5f892b3f06decec8c7bb795b154b940c15b86 100644
--- a/src/vs/workbench/api/node/extHostFileSystemEventService.ts
+++ b/src/vs/workbench/api/node/extHostFileSystemEventService.ts
@@ -9,6 +9,7 @@ import { Disposable } from './extHostTypes';
 import { parse, IRelativePattern } from 'vs/base/common/glob';
 import { Uri, FileSystemWatcher as _FileSystemWatcher } from 'vscode';
 import { FileSystemEvents, ExtHostFileSystemEventServiceShape } from './extHost.protocol';
+import URI from 'vs/base/common/uri';
 
 class FileSystemWatcher implements _FileSystemWatcher {
 
@@ -48,22 +49,25 @@ class FileSystemWatcher implements _FileSystemWatcher {
 		let subscription = dispatcher(events => {
 			if (!ignoreCreateEvents) {
 				for (let created of events.created) {
-					if (parsedPattern(created.fsPath)) {
-						this._onDidCreate.fire(created);
+					let uri = URI.revive(created);
+					if (parsedPattern(uri.fsPath)) {
+						this._onDidCreate.fire(uri);
 					}
 				}
 			}
 			if (!ignoreChangeEvents) {
 				for (let changed of events.changed) {
-					if (parsedPattern(changed.fsPath)) {
-						this._onDidChange.fire(changed);
+					let uri = URI.revive(changed);
+					if (parsedPattern(uri.fsPath)) {
+						this._onDidChange.fire(uri);
 					}
 				}
 			}
 			if (!ignoreDeleteEvents) {
 				for (let deleted of events.deleted) {
-					if (parsedPattern(deleted.fsPath)) {
-						this._onDidDelete.fire(deleted);
+					let uri = URI.revive(deleted);
+					if (parsedPattern(uri.fsPath)) {
+						this._onDidDelete.fire(uri);
 					}
 				}
 			}