diff --git a/dist/index.js b/dist/index.js
index 2369bfc..0074e0a 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1400,7 +1400,10 @@ function getFetchUrl(settings) {
 }
 exports.getFetchUrl = getFetchUrl;
 function getServerUrl() {
-    return new url_1.URL(process.env['GITHUB_URL'] || 'https://github.com');
+    // todo: remove GITHUB_URL after support for GHES Alpha is no longer needed
+    return new url_1.URL(process.env['GITHUB_SERVER_URL'] ||
+        process.env['GITHUB_URL'] ||
+        'https://github.com');
 }
 exports.getServerUrl = getServerUrl;
 
diff --git a/src/url-helper.ts b/src/url-helper.ts
index 31848c7..05f1cbd 100644
--- a/src/url-helper.ts
+++ b/src/url-helper.ts
@@ -20,5 +20,10 @@ export function getFetchUrl(settings: IGitSourceSettings): string {
 }
 
 export function getServerUrl(): URL {
-  return new URL(process.env['GITHUB_URL'] || 'https://github.com')
+  // todo: remove GITHUB_URL after support for GHES Alpha is no longer needed
+  return new URL(
+    process.env['GITHUB_SERVER_URL'] ||
+      process.env['GITHUB_URL'] ||
+      'https://github.com'
+  )
 }