diff --git a/README.md b/README.md
index 8fe140f..de277a0 100644
--- a/README.md
+++ b/README.md
@@ -98,8 +98,9 @@ When Git 2.18 or higher is not in your PATH, falls back to the REST API to downl
 
     # The base URL for the GitHub instance that you are trying to clone from, will use
     # environment defaults to fetch from the same instance that the workflow is
-    # running from unless specified. Example URLs are https://github.com or
-    # https://my-ghes-server.example.com
+    # running from unless specified. Also support URL pathname except SSH (`ssh-key`
+    # not specified). Example URLs are https://github.com or
+    # https://my-ghes-server.example.com or https://my-ghes-server.example.com/git/
     github-server-url: ''
 ```
 <!-- end usage -->
diff --git a/action.yml b/action.yml
index cab09eb..f8c29a6 100644
--- a/action.yml
+++ b/action.yml
@@ -72,7 +72,7 @@ inputs:
     description: Add repository path as safe.directory for Git global config by running `git config --global --add safe.directory <path>`
     default: true
   github-server-url:
-    description: The base URL for the GitHub instance that you are trying to clone from, will use environment defaults to fetch from the same instance that the workflow is running from unless specified. Example URLs are https://github.com or https://my-ghes-server.example.com
+    description: The base URL for the GitHub instance that you are trying to clone from, will use environment defaults to fetch from the same instance that the workflow is running from unless specified. Also support URL pathname except SSH (`ssh-key` not specified). Example URLs are https://github.com or https://my-ghes-server.example.com or https://my-ghes-server.example.com/git/
     required: false
 runs:
   using: node16
diff --git a/dist/index.js b/dist/index.js
index e6f5df8..a09d185 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -163,13 +163,14 @@ class GitAuthHelper {
         this.settings = gitSourceSettings || {};
         // Token auth header
         const serverUrl = urlHelper.getServerUrl(this.settings.githubServerUrl);
-        this.tokenConfigKey = `http.${serverUrl.origin}/.extraheader`; // "origin" is SCHEME://HOSTNAME[:PORT]
+        const baseURL = urlHelper.getBaseUrl(serverUrl.href);
+        this.tokenConfigKey = `http.${baseURL}/.extraheader`; // "origin" is SCHEME://HOSTNAME[:PORT]
         const basicCredential = Buffer.from(`x-access-token:${this.settings.authToken}`, 'utf8').toString('base64');
         core.setSecret(basicCredential);
         this.tokenPlaceholderConfigValue = `AUTHORIZATION: basic ***`;
         this.tokenConfigValue = `AUTHORIZATION: basic ${basicCredential}`;
         // Instead of SSH URL
-        this.insteadOfKey = `url.${serverUrl.origin}/.insteadOf`; // "origin" is SCHEME://HOSTNAME[:PORT]
+        this.insteadOfKey = `url.${baseURL}/.insteadOf`; // "origin" is SCHEME://HOSTNAME[:PORT]
         this.insteadOfValues.push(`git@${serverUrl.hostname}:`);
         if (this.settings.workflowOrganizationId) {
             this.insteadOfValues.push(`org-${this.settings.workflowOrganizationId}@github.com:`);
@@ -2294,7 +2295,7 @@ var __importStar = (this && this.__importStar) || function (mod) {
     return result;
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
-exports.isGhes = exports.getServerApiUrl = exports.getServerUrl = exports.getFetchUrl = void 0;
+exports.isGhes = exports.getServerApiUrl = exports.getBaseUrl = exports.getServerUrl = exports.getFetchUrl = void 0;
 const assert = __importStar(__nccwpck_require__(9491));
 const url_1 = __nccwpck_require__(7310);
 function getFetchUrl(settings) {
@@ -2307,16 +2308,22 @@ function getFetchUrl(settings) {
         return `git@${serviceUrl.hostname}:${encodedOwner}/${encodedName}.git`;
     }
     // "origin" is SCHEME://HOSTNAME[:PORT]
-    return `${serviceUrl.origin}/${encodedOwner}/${encodedName}`;
+    const baseURL = getBaseUrl(serviceUrl.href);
+    return `${baseURL}/${encodedOwner}/${encodedName}`;
 }
 exports.getFetchUrl = getFetchUrl;
 function getServerUrl(url) {
-    let urlValue = url && url.trim().length > 0
+    const urlValue = url && url.trim().length > 0
         ? url
         : process.env['GITHUB_SERVER_URL'] || 'https://github.com';
     return new url_1.URL(urlValue);
 }
 exports.getServerUrl = getServerUrl;
+function getBaseUrl(url) {
+    const matcher = url.match(/^[^?]+/);
+    return (matcher && matcher[0].replace(/\/+$/g, '')) || '';
+}
+exports.getBaseUrl = getBaseUrl;
 function getServerApiUrl(url) {
     let apiUrl = 'https://api.github.com';
     if (isGhes(url)) {
diff --git a/src/git-auth-helper.ts b/src/git-auth-helper.ts
index 364a04e..b5a6cf0 100644
--- a/src/git-auth-helper.ts
+++ b/src/git-auth-helper.ts
@@ -53,7 +53,8 @@ class GitAuthHelper {
 
     // Token auth header
     const serverUrl = urlHelper.getServerUrl(this.settings.githubServerUrl)
-    this.tokenConfigKey = `http.${serverUrl.origin}/.extraheader` // "origin" is SCHEME://HOSTNAME[:PORT]
+    const baseURL = urlHelper.getBaseUrl(serverUrl.href)
+    this.tokenConfigKey = `http.${baseURL}/.extraheader` // "origin" is SCHEME://HOSTNAME[:PORT]
     const basicCredential = Buffer.from(
       `x-access-token:${this.settings.authToken}`,
       'utf8'
@@ -63,7 +64,7 @@ class GitAuthHelper {
     this.tokenConfigValue = `AUTHORIZATION: basic ${basicCredential}`
 
     // Instead of SSH URL
-    this.insteadOfKey = `url.${serverUrl.origin}/.insteadOf` // "origin" is SCHEME://HOSTNAME[:PORT]
+    this.insteadOfKey = `url.${baseURL}/.insteadOf` // "origin" is SCHEME://HOSTNAME[:PORT]
     this.insteadOfValues.push(`git@${serverUrl.hostname}:`)
     if (this.settings.workflowOrganizationId) {
       this.insteadOfValues.push(
diff --git a/src/url-helper.ts b/src/url-helper.ts
index 6807b7f..d12a82a 100644
--- a/src/url-helper.ts
+++ b/src/url-helper.ts
@@ -16,17 +16,23 @@ export function getFetchUrl(settings: IGitSourceSettings): string {
   }
 
   // "origin" is SCHEME://HOSTNAME[:PORT]
-  return `${serviceUrl.origin}/${encodedOwner}/${encodedName}`
+  const baseURL = getBaseUrl(serviceUrl.href)
+  return `${baseURL}/${encodedOwner}/${encodedName}`
 }
 
 export function getServerUrl(url?: string): URL {
-  let urlValue =
+  const urlValue =
     url && url.trim().length > 0
       ? url
       : process.env['GITHUB_SERVER_URL'] || 'https://github.com'
   return new URL(urlValue)
 }
 
+export function getBaseUrl(url: string): string {
+  const matcher = url.match(/^[^?]+/)
+  return (matcher && matcher[0].replace(/\/+$/g, '')) || ''
+}
+
 export function getServerApiUrl(url?: string): string {
   let apiUrl = 'https://api.github.com'