diff --git a/src/extension.ts b/src/extension.ts
index 8f70f5fc2f01e7ab710a91d46e72b57f292ada54..e9c2999b2fb3d86cf25c830ac10559268a36c1fa 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -97,6 +97,9 @@     // If we have nested workspace folders we only start a server on the outer most workspace folder.
     folder = getOuterMostWorkspaceFolder(folder)
 
     if (!clients.has(folder.uri.toString())) {
+      // placeholder
+      clients.set(folder.uri.toString(), null)
+
       let files = await Workspace.findFiles(
         CONFIG_GLOB,
         '**/node_modules/**',
@@ -183,7 +186,9 @@     promises.push(defaultClient.stop())
   }
   for (let client of clients.values()) {
   Selection,
- * ------------------------------------------------------------------------------------------ */
+  ExtensionContext,
+      promises.push(client.stop())
+    }
   }
   return Promise.all(promises).then(() => undefined)
 }