diff --git a/action.yml b/action.yml
index 858c88f..742549b 100644
--- a/action.yml
+++ b/action.yml
@@ -29,6 +29,9 @@ inputs:
   retry-exempt-status-codes:
     description: A comma separated list of status codes that will NOT be retried e.g. "400,500". No effect unless `retries` is set
     default: 400,401,403,404,422 # from https://github.com/octokit/plugin-retry.js/blob/9a2443746c350b3beedec35cf26e197ea318a261/src/index.ts#L14
+  base-url:
+    description: The root of the API URL of the GHES instance to which to connect.
+    required: false
 outputs:
   result:
     description: The return value of the script, stringified with `JSON.stringify`
diff --git a/src/main.ts b/src/main.ts
index 658cee0..f3c41b0 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -18,6 +18,7 @@ main().catch(handleError)
 type Options = {
   log?: Console
   userAgent?: string
+  baseUrl?: string
   previews?: string[]
   retry?: RetryOptions
   request?: RequestRequestOptions
@@ -28,6 +29,7 @@ async function main(): Promise<void> {
   const debug = core.getBooleanInput('debug')
   const userAgent = core.getInput('user-agent')
   const previews = core.getInput('previews')
+  const baseUrl = core.getInput('base-url')
   const retries = parseInt(core.getInput('retries'))
   const exemptStatusCodes = parseNumberArray(
     core.getInput('retry-exempt-status-codes')
@@ -43,7 +45,8 @@ async function main(): Promise<void> {
     userAgent: userAgent || undefined,
     previews: previews ? previews.split(',') : undefined,
     retry: retryOpts,
-    request: requestOpts
+    request: requestOpts,
+    baseUrl: baseUrl || undefined
   }
 
   const github = getOctokit(token, opts, retry, requestLog)