diff --git a/src/vs/workbench/node/extensionHostMain.ts b/src/vs/workbench/node/extensionHostMain.ts
index 7adcb13e853..4008bae8e48 100644
--- a/src/vs/workbench/node/extensionHostMain.ts
+++ b/src/vs/workbench/node/extensionHostMain.ts
@@ -93,6 +93,8 @@ export class ExtensionHostMain {
 		// services
 		const rpcProtocol = new RPCProtocol(protocol);
 		this._workspace = rpcProtocol.transformIncomingURIs(initData.workspace);
+		// ensure URIs are revived
+		initData.extensions.forEach((ext) => (<any>ext).extensionLocation = URI.revive(ext.extensionLocation));
 
 		this._extHostLogService = new ExtHostLogService(initData.windowId, initData.logLevel, initData.logsPath);
 		this.disposables.push(this._extHostLogService);