diff --git a/package.json b/package.json
index 4bed5a0ed75..5c06dcc5d7a 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
   "scripts": {
     "test": "node node_modules/mocha/bin/_mocha",
     "preinstall": "node build/npm/preinstall.js",
-    "postinstall": "npm --prefix extensions/vscode-api-tests/ install extensions/vscode-api-tests/ && npm --prefix extensions/json/ install"
+    "postinstall": "npm --prefix extensions/vscode-api-tests/ install extensions/vscode-api-tests/ && npm --prefix extensions/json/ install extensions/json/"
   },
   "dependencies": {
     "applicationinsights": "0.15.6",