diff --git a/src/vs/platform/workspace/common/workspace.ts b/src/vs/platform/workspace/common/workspace.ts
index 7b66a268eedf68f50a76cbc7f0f0a46cc8e40b5a..f1af73f02ad5d03bae9360ec7df8c3c1b8f80ae0 100644
--- a/src/vs/platform/workspace/common/workspace.ts
+++ b/src/vs/platform/workspace/common/workspace.ts
@@ -34,7 +34,7 @@ export interface IWorkspaceContextService {
 	 * without leading or trailing slashes. Returns null if the file is not inside an opened
 	 * workspace.
 	 */
-	toWorkspaceRelativePath: (resource: URI) => string;
+	toWorkspaceRelativePath: (resource: URI, toOSPath?: boolean) => string;
 
 	/**
 	 * Given a workspace relative path, returns the resource with the absolute path.
@@ -89,9 +89,9 @@ export class WorkspaceContextService implements IWorkspaceContextService {
 		return false;
 	}
 
-	public toWorkspaceRelativePath(resource: URI): string {
+	public toWorkspaceRelativePath(resource: URI, toOSPath?: boolean): string {
 		if (this.isInsideWorkspace(resource)) {
-			return paths.normalize(paths.relative(this.workspace.resource.fsPath, resource.fsPath));
+			return paths.normalize(paths.relative(this.workspace.resource.fsPath, resource.fsPath), toOSPath);
 		}
 
 		return null;
diff --git a/src/vs/workbench/parts/files/browser/views/explorerViewer.ts b/src/vs/workbench/parts/files/browser/views/explorerViewer.ts
index 305779e9dec6e61633d5dbf0f2b0ac3846ac1145..a4aa43bf9fb946118c9de14d4da010dce7d593df 100644
--- a/src/vs/workbench/parts/files/browser/views/explorerViewer.ts
+++ b/src/vs/workbench/parts/files/browser/views/explorerViewer.ts
@@ -602,7 +602,7 @@ export class FileFilter implements IFilter {
 
 		// Hide those that match Hidden Patterns
 		const siblingsFn = () => siblings && siblings.map(c => c.name);
-		if (glob.match(this.hiddenExpression, this.contextService.toWorkspaceRelativePath(stat.resource), siblingsFn)) {
+		if (glob.match(this.hiddenExpression, this.contextService.toWorkspaceRelativePath(stat.resource, true), siblingsFn)) {
 			return false; // hidden through pattern
 		}
 
diff --git a/src/vs/workbench/test/workbenchTestServices.ts b/src/vs/workbench/test/workbenchTestServices.ts
index bda563c616eda4ecdd2e4e982d3e2688ae32ff8e..6fcfa139324a1cbae24dd1b117c116e4eeaceb8a 100644
--- a/src/vs/workbench/test/workbenchTestServices.ts
+++ b/src/vs/workbench/test/workbenchTestServices.ts
@@ -96,8 +96,8 @@ export class TestContextService implements IWorkspaceContextService {
 		return false;
 	}
 
-	public toWorkspaceRelativePath(resource: URI): string {
-		return paths.makePosixAbsolute(paths.normalize(resource.fsPath.substr('c:'.length)));
+	public toWorkspaceRelativePath(resource: URI, toOSPath?: boolean): string {
+		return paths.makePosixAbsolute(paths.normalize(resource.fsPath.substr('c:'.length), toOSPath));
 	}
 
 	public toResource(workspaceRelativePath: string): URI {