diff --git a/src/vs/workbench/api/electron-browser/mainThreadDocuments.ts b/src/vs/workbench/api/electron-browser/mainThreadDocuments.ts
index ab8a158398fd023089782619fe07a21b7f4653ad..4d1f5845bda91f5c3fd87bc1360dea9c0d3da732 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadDocuments.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadDocuments.ts
@@ -104,17 +104,17 @@ export class MainThreadDocuments implements MainThreadDocumentsShape {
 
 		this._toDispose.push(textFileService.models.onModelSaved(e => {
 			if (this._shouldHandleFileEvent(e)) {
-				this._proxy.$acceptModelSaved(e.resource.toString());
+				this._proxy.$acceptModelSaved(e.resource);
 			}
 		}));
 		this._toDispose.push(textFileService.models.onModelReverted(e => {
 			if (this._shouldHandleFileEvent(e)) {
-				this._proxy.$acceptDirtyStateChanged(e.resource.toString(), false);
+				this._proxy.$acceptDirtyStateChanged(e.resource, false);
 			}
 		}));
 		this._toDispose.push(textFileService.models.onModelDirty(e => {
 			if (this._shouldHandleFileEvent(e)) {
-				this._proxy.$acceptDirtyStateChanged(e.resource.toString(), true);
+				this._proxy.$acceptDirtyStateChanged(e.resource, true);
 			}
 		}));
 
@@ -143,7 +143,7 @@ export class MainThreadDocuments implements MainThreadDocumentsShape {
 		let modelUrl = model.uri;
 		this._modelIsSynced[modelUrl.toString()] = true;
 		this._modelToDisposeMap[modelUrl.toString()] = model.onDidChangeContent((e) => {
-			this._proxy.$acceptModelChanged(modelUrl.toString(), e, this._textFileService.isDirty(modelUrl));
+			this._proxy.$acceptModelChanged(modelUrl, e, this._textFileService.isDirty(modelUrl));
 		});
 	}
 
@@ -153,7 +153,7 @@ export class MainThreadDocuments implements MainThreadDocumentsShape {
 		if (!this._modelIsSynced[modelUrl.toString()]) {
 			return;
 		}
-		this._proxy.$acceptModelModeChanged(model.uri.toString(), oldModeId, model.getLanguageIdentifier().language);
+		this._proxy.$acceptModelModeChanged(model.uri, oldModeId, model.getLanguageIdentifier().language);
 	}
 
 	private _onModelRemoved(modelUrl: URI): void {
@@ -227,7 +227,7 @@ export class MainThreadDocuments implements MainThreadDocumentsShape {
 				throw new Error(`expected URI ${resource.toString()} to have come to LIFE`);
 			}
 
-			this._proxy.$acceptDirtyStateChanged(resource.toString(), true); // mark as dirty
+			this._proxy.$acceptDirtyStateChanged(resource, true); // mark as dirty
 
 			return resource;
 		});
diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index 32ac780d5c361e6682485279d0a1be63368cad97..746252ccab77bcac906a61dee655fe0a94e1e414 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -479,10 +479,10 @@ export interface IModelAddedData {
 	isDirty: boolean;
 }
 export interface ExtHostDocumentsShape {
-	$acceptModelModeChanged(strURL: string, oldModeId: string, newModeId: string): void;
-	$acceptModelSaved(strURL: string): void;
-	$acceptDirtyStateChanged(strURL: string, isDirty: boolean): void;
-	$acceptModelChanged(strURL: string, e: IModelChangedEvent, isDirty: boolean): void;
+	$acceptModelModeChanged(strURL: UriComponents, oldModeId: string, newModeId: string): void;
+	$acceptModelSaved(strURL: UriComponents): void;
+	$acceptDirtyStateChanged(strURL: UriComponents, isDirty: boolean): void;
+	$acceptModelChanged(strURL: UriComponents, e: IModelChangedEvent, isDirty: boolean): void;
 }
 
 export interface ExtHostDocumentSaveParticipantShape {
diff --git a/src/vs/workbench/api/node/extHostDocuments.ts b/src/vs/workbench/api/node/extHostDocuments.ts
index c92d98c77212b8a196ae514f4735ca830d47132a..eb0b12fd915c5a03e0d29cba59e88cfef853c6fd 100644
--- a/src/vs/workbench/api/node/extHostDocuments.ts
+++ b/src/vs/workbench/api/node/extHostDocuments.ts
@@ -5,7 +5,7 @@
 'use strict';
 
 import Event, { Emitter } from 'vs/base/common/event';
-import URI from 'vs/base/common/uri';
+import URI, { UriComponents } from 'vs/base/common/uri';
 import { IDisposable, dispose } from 'vs/base/common/lifecycle';
 import * as TypeConverters from './extHostTypeConverters';
 import { TPromise } from 'vs/base/common/winjs.base';
@@ -95,7 +95,9 @@ export class ExtHostDocuments implements ExtHostDocumentsShape {
 		return this._proxy.$tryCreateDocument(options).then(data => URI.revive(data));
 	}
 
-	public $acceptModelModeChanged(strURL: string, oldModeId: string, newModeId: string): void {
+	public $acceptModelModeChanged(uriComponents: UriComponents, oldModeId: string, newModeId: string): void {
+		const uri = URI.revive(uriComponents);
+		const strURL = uri.toString();
 		let data = this._documentsAndEditors.getDocument(strURL);
 
 		// Treat a mode change as a remove + add
@@ -105,13 +107,17 @@ export class ExtHostDocuments implements ExtHostDocumentsShape {
 		this._onDidAddDocument.fire(data.document);
 	}
 
-	public $acceptModelSaved(strURL: string): void {
+	public $acceptModelSaved(uriComponents: UriComponents): void {
+		const uri = URI.revive(uriComponents);
+		const strURL = uri.toString();
 		let data = this._documentsAndEditors.getDocument(strURL);
-		this.$acceptDirtyStateChanged(strURL, false);
+		this.$acceptDirtyStateChanged(uriComponents, false);
 		this._onDidSaveDocument.fire(data.document);
 	}
 
-	public $acceptDirtyStateChanged(strURL: string, isDirty: boolean): void {
+	public $acceptDirtyStateChanged(uriComponents: UriComponents, isDirty: boolean): void {
+		const uri = URI.revive(uriComponents);
+		const strURL = uri.toString();
 		let data = this._documentsAndEditors.getDocument(strURL);
 		data._acceptIsDirty(isDirty);
 		this._onDidChangeDocument.fire({
@@ -120,7 +126,9 @@ export class ExtHostDocuments implements ExtHostDocumentsShape {
 		});
 	}
 
-	public $acceptModelChanged(strURL: string, events: IModelChangedEvent, isDirty: boolean): void {
+	public $acceptModelChanged(uriComponents: UriComponents, events: IModelChangedEvent, isDirty: boolean): void {
+		const uri = URI.revive(uriComponents);
+		const strURL = uri.toString();
 		let data = this._documentsAndEditors.getDocument(strURL);
 		data._acceptIsDirty(isDirty);
 		data.onEvents(events);
diff --git a/src/vs/workbench/test/electron-browser/api/extHostDocumentSaveParticipant.test.ts b/src/vs/workbench/test/electron-browser/api/extHostDocumentSaveParticipant.test.ts
index 8ec74bfb0735e76e04ec4fee1e8c0b22bd62a03d..d50d46f226a059d43e0f2e98eb2c148f953a3c8c 100644
--- a/src/vs/workbench/test/electron-browser/api/extHostDocumentSaveParticipant.test.ts
+++ b/src/vs/workbench/test/electron-browser/api/extHostDocumentSaveParticipant.test.ts
@@ -298,7 +298,7 @@ suite('ExtHostDocumentSaveParticipant', () => {
 		let sub = participant.getOnWillSaveTextDocumentEvent(nullExtensionDescription)(function (e) {
 
 			// concurrent change from somewhere
-			documents.$acceptModelChanged(resource.toString(), {
+			documents.$acceptModelChanged(resource, {
 				changes: [{
 					range: { startLineNumber: 1, startColumn: 1, endLineNumber: 1, endColumn: 1 },
 					rangeLength: undefined,
@@ -332,7 +332,7 @@ suite('ExtHostDocumentSaveParticipant', () => {
 					const { resource, edits } = edit;
 					const uri = URI.revive(resource);
 					for (const { text, range } of edits) {
-						documents.$acceptModelChanged(uri.toString(), {
+						documents.$acceptModelChanged(uri, {
 							changes: [{
 								range,
 								text,