diff --git a/appveyor.yml b/appveyor.yml
index 537c294b4..6e20fd72f 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -7,21 +7,22 @@ skip_branch_with_pr: true
 skip_tags: true
 
 cache:
- - '%LOCALAPPDATA%\Yarn'
+ - '%AppData%/npm-cache'
 
 environment:
   NODEJS_VERSION: '8.9.4'
 
 install:
   - ps: Install-Product node $env:NODEJS_VERSION
-  - yarn install
+  - npm install -g npm@6.0.0
+  - npm ci
 
 build_script:
-  - yarn run build
+  - npm run build
 
 test_script:
-  - yarn run lint
-  - yarn run cover
+  - npm run lint
+  - npm run cover
 
 after_test:
   - ps: |
diff --git a/src/plugins.ts b/src/plugins.ts
index bed3e977e..8436e9948 100644
--- a/src/plugins.ts
+++ b/src/plugins.ts
@@ -40,9 +40,8 @@ export interface PluginCreateInfo {
  * The portion of tsserver's Project API exposed to plugins
  */
 export interface Project {
-    projectService: {
-        logger: Logger
-    }
+    projectService: { logger: Logger }
+    getCurrentDirectory(): string
 }
 
 /**
diff --git a/src/project-manager.ts b/src/project-manager.ts
index c47e06446..4d6a104b0 100644
--- a/src/project-manager.ts
+++ b/src/project-manager.ts
@@ -385,7 +385,11 @@ export class ProjectConfiguration {
 
             const info: PluginCreateInfo = {
                 config: configEntry,
-                project: { projectService: { logger: this.logger } }, // TODO: may need more support
+                project: {
+                    // TODO: may need more support
+                    getCurrentDirectory: () => this.getHost().getCurrentDirectory(),
+                    projectService: { logger: this.logger },
+                },
                 languageService: this.getService(),
                 languageServiceHost: this.getHost(),
                 serverHost: {}, // TODO: may need an adapter