diff --git a/extensions/typescript-language-features/src/features/bufferSyncSupport.ts b/extensions/typescript-language-features/src/features/bufferSyncSupport.ts
index c2faca72c50..e85414f5734 100644
--- a/extensions/typescript-language-features/src/features/bufferSyncSupport.ts
+++ b/extensions/typescript-language-features/src/features/bufferSyncSupport.ts
@@ -364,7 +364,3 @@ export default class BufferSyncSupport {
 		return this.client.normalizedPath(path);
 	}
 }
-
-export function isWindowsPath(path: string): boolean {
-	return /^[a-zA-Z]:\\/.test(path);
-}
diff --git a/extensions/typescript-language-features/src/features/diagnostics.ts b/extensions/typescript-language-features/src/features/diagnostics.ts
index e2884f74d36..0fe5d8b4e67 100644
--- a/extensions/typescript-language-features/src/features/diagnostics.ts
+++ b/extensions/typescript-language-features/src/features/diagnostics.ts
@@ -4,27 +4,24 @@
  *--------------------------------------------------------------------------------------------*/
 
 import *  as vscode from 'vscode';
+import { ResourceMap } from './resourceMap';
 
 export class DiagnosticSet {
-	private _map: ObjectMap<vscode.Diagnostic[]> = Object.create(null);
+	private _map = new ResourceMap<vscode.Diagnostic[]>();
 
 	public set(
 		file: vscode.Uri,
 		diagnostics: vscode.Diagnostic[]
 	) {
-		this._map[this.key(file)] = diagnostics;
+		this._map.set(file, diagnostics);
 	}
 
 	public get(file: vscode.Uri): vscode.Diagnostic[] {
-		return this._map[this.key(file)] || [];
+		return this._map.get(file) || [];
 	}
 
 	public clear(): void {
-		this._map = Object.create(null);
-	}
-
-	private key(file: vscode.Uri): string {
-		return file.toString(true);
+		this._map = new ResourceMap<vscode.Diagnostic[]>();
 	}
 }
 
@@ -40,7 +37,7 @@ export class DiagnosticsManager {
 
 	private readonly _diagnostics = new Map<DiagnosticKind, DiagnosticSet>();
 	private readonly _currentDiagnostics: vscode.DiagnosticCollection;
-	private readonly _pendingUpdates: { [key: string]: any } = Object.create(null);
+	private _pendingUpdates = new ResourceMap<any>();
 	private _validate: boolean = true;
 	private _enableSuggestions: boolean = true;
 
@@ -59,10 +56,10 @@ export class DiagnosticsManager {
 	public dispose() {
 		this._currentDiagnostics.dispose();
 
-		for (const key of Object.keys(this._pendingUpdates)) {
-			clearTimeout(this._pendingUpdates[key]);
-			delete this._pendingUpdates[key];
+		for (const value of this._pendingUpdates.values) {
+			clearTimeout(value);
 		}
+		this._pendingUpdates = new ResourceMap<any>();
 	}
 
 	public reInitialize(): void {
@@ -131,16 +128,15 @@ export class DiagnosticsManager {
 	}
 
 	private scheduleDiagnosticsUpdate(file: vscode.Uri) {
-		const key = file.fsPath;
-		if (!this._pendingUpdates[key]) {
-			this._pendingUpdates[key] = setTimeout(() => this.updateCurrentDiagnostics(file), this.updateDelay);
+		if (!this._pendingUpdates.has(file)) {
+			this._pendingUpdates.set(file, setTimeout(() => this.updateCurrentDiagnostics(file), this.updateDelay));
 		}
 	}
 
 	private updateCurrentDiagnostics(file: vscode.Uri) {
-		if (this._pendingUpdates[file.fsPath]) {
-			clearTimeout(this._pendingUpdates[file.fsPath]);
-			delete this._pendingUpdates[file.fsPath];
+		if (this._pendingUpdates.has(file)) {
+			clearTimeout(this._pendingUpdates.get(file));
+			this._pendingUpdates.delete(file);
 		}
 
 		if (!this._validate) {
diff --git a/extensions/typescript-language-features/src/features/resourceMap.ts b/extensions/typescript-language-features/src/features/resourceMap.ts
index 22959a08b89..876db56dd0c 100644
--- a/extensions/typescript-language-features/src/features/resourceMap.ts
+++ b/extensions/typescript-language-features/src/features/resourceMap.ts
@@ -7,7 +7,6 @@ import * as fs from 'fs';
 import { Uri } from 'vscode';
 import { memoize } from '../utils/memoize';
 import { getTempFile } from '../utils/temp';
-import { isWindowsPath } from './bufferSyncSupport';
 
 /**
  * Maps of file resources
@@ -19,7 +18,7 @@ export class ResourceMap<T> {
 	private readonly _map = new Map<string, T>();
 
 	constructor(
-		private readonly _normalizePath: (resource: Uri) => string | null
+		private readonly _normalizePath?: (resource: Uri) => string | null
 	) { }
 
 	public has(resource: Uri): boolean {
@@ -55,7 +54,7 @@ export class ResourceMap<T> {
 	}
 
 	private toKey(resource: Uri): string | null {
-		const key = this._normalizePath(resource);
+		const key = this._normalizePath ? this._normalizePath(resource) : resource.toString(true);
 		if (!key) {
 			return key;
 		}
@@ -82,3 +81,7 @@ export class ResourceMap<T> {
 		return fs.existsSync(temp.toUpperCase());
 	}
 }
+
+export function isWindowsPath(path: string): boolean {
+	return /^[a-zA-Z]:\\/.test(path);
+}