diff --git a/appveyor.yml b/appveyor.yml
index ca5a95539..00358c3bf 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -10,7 +10,6 @@ platform:
 
 install:
   - ps: Install-Product node 10 x64
-  - yarn
 
 build_script:
   - npm install
diff --git a/package.json b/package.json
index d24711fad..328807e02 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
     "linter": "./node_modules/.bin/eslint --resolve-plugins-relative-to . --fix --quiet --ext .js --ext .jsx --ext .ts --ext .tsx",
     "linter-precommit": "./node_modules/.bin/eslint --resolve-plugins-relative-to . --fix --ext .js --ext .jsx --ext .ts --ext .tsx",
     "linter-ci": "./node_modules/.bin/eslint --resolve-plugins-relative-to . --quiet --ext .js --ext .jsx --ext .ts --ext .tsx",
-    "postinstall": "lerna bootstrap && npm run tsc",
+    "postinstall": "lerna bootstrap --no-ci && npm run tsc",
     "tsc": "lerna run tsc --stream --parallel",
     "watch": "lerna run watch --stream --parallel",
     "updateIgnored": "gulp updateIgnoredTypeScriptBuild",