diff --git a/index.js b/index.js
index 00d5b46..5f87637 100644
--- a/index.js
+++ b/index.js
@@ -5,8 +5,8 @@ const { EOL } = require('os');
 const path = require('path');
 
 // Change working directory if user defined PACKAGEJSON_DIR
-if (process.env.PACKAGEJSON_DIR) {
-  process.env.GITHUB_WORKSPACE = `${process.env.GITHUB_WORKSPACE}/${process.env.PACKAGEJSON_DIR}`;
+if (process.env.INPUT_PACKAGEJSON_DIR) {
+  process.env.GITHUB_WORKSPACE = `${process.env.GITHUB_WORKSPACE}/${process.env.INPUT_PACKAGEJSON_DIR}`;
   process.chdir(process.env.GITHUB_WORKSPACE);
 }