diff --git a/src/vs/platform/workspace/common/workspace.ts b/src/vs/platform/workspace/common/workspace.ts
index af594644baea5cda0d6cea6df7cfeae2920040e0..1493935a0130b439f345b8aaccdfd06529b5bcad 100644
--- a/src/vs/platform/workspace/common/workspace.ts
+++ b/src/vs/platform/workspace/common/workspace.ts
@@ -198,7 +198,7 @@ export class Workspace implements IWorkspace {
 	}
 
 	public toJSON(): IWorkspace {
-		return { id: this.id, folders: this.folders, name: this.name };
+		return { id: this.id, folders: this.folders, name: this.name, configuration: this.configuration };
 	}
 }
 
diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index d4dcd03d36370a0bc79ccc71c12f1bfaae1e6454..faacf07efa71aa04a4a3ec20d09fe6fe466d43b5 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -71,6 +71,7 @@ export interface IWorkspaceData {
 	id: string;
 	name: string;
 	folders: { uri: UriComponents, name: string, index: number }[];
+	configuration: UriComponents;
 }
 
 export interface IInitData {
diff --git a/src/vs/workbench/api/node/extHostExtensionService.ts b/src/vs/workbench/api/node/extHostExtensionService.ts
index d39a58a432e2fbf6513aa1c846cb0c0ca72dbb18..73a8df57d4e0a8802a30c756dc7050e20e6d6537 100644
--- a/src/vs/workbench/api/node/extHostExtensionService.ts
+++ b/src/vs/workbench/api/node/extHostExtensionService.ts
@@ -22,6 +22,7 @@ import { Barrier } from 'vs/base/common/async';
 import { ILogService } from 'vs/platform/log/common/log';
 import { IEnvironmentService } from 'vs/platform/environment/common/environment';
 import { ExtHostLogService } from 'vs/workbench/api/node/extHostLogService';
+import URI from 'vs/base/common/uri';
 
 class ExtensionMemento implements IExtensionMemento {
 
@@ -108,6 +109,7 @@ class ExtensionStoragePath {
 				join(storagePath, 'meta.json'),
 				JSON.stringify({
 					id: this._workspace.id,
+					configuration: URI.revive(this._workspace.configuration).toString(),
 					name: this._workspace.name
 				}, undefined, 2)
 			);