diff --git a/README.md b/README.md
index f0f65f9..dce0e8d 100644
--- a/README.md
+++ b/README.md
@@ -160,6 +160,10 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
     # running from unless specified. Example URLs are https://github.com or
     # https://my-ghes-server.example.com
     github-server-url: ''
+
+    # Set Git object format to "sha256" when initializing a Git repository.
+    # Default: false
+    repo-sha256: ''
 ```
 <!-- end usage -->
 
diff --git a/action.yml b/action.yml
index 767c416..b81a4d5 100644
--- a/action.yml
+++ b/action.yml
@@ -98,6 +98,10 @@ inputs:
   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
     required: false
+  repo-sha256:
+    description: 'Set Git object format to "sha256" when initializing a Git repository.'
+    required: false
+    default: false
 outputs:
   ref:
     description: 'The branch, tag or SHA that was checked out'
diff --git a/dist/index.js b/dist/index.js
index fe3f317..2317305 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -896,9 +896,14 @@ class GitCommandManager {
     getWorkingDirectory() {
         return this.workingDirectory;
     }
-    init() {
+    init(repoSHA256) {
         return __awaiter(this, void 0, void 0, function* () {
-            yield this.execGit(['init', this.workingDirectory]);
+            const args = ['init'];
+            if (repoSHA256) {
+                args.push(`--object-format=sha256`);
+            }
+            args.push(this.workingDirectory);
+            yield this.execGit(args);
         });
     }
     isDetached() {
@@ -1487,7 +1492,7 @@ function getSource(settings) {
             // Initialize the repository
             if (!fsHelper.directoryExistsSync(path.join(settings.repositoryPath, '.git'))) {
                 core.startGroup('Initializing the repository');
-                yield git.init();
+                yield git.init(settings.repoSHA256);
                 yield git.remoteAdd('origin', repositoryUrl);
                 core.endGroup();
             }
@@ -2095,6 +2100,10 @@ function getInputs() {
         // Determine the GitHub URL that the repository is being hosted from
         result.githubServerUrl = core.getInput('github-server-url');
         core.debug(`GitHub Host URL = ${result.githubServerUrl}`);
+        // Set Git object format to "sha256" when initializing a Git repository.
+        result.repoSHA256 =
+            (core.getInput('repo-sha256') || 'false').toUpperCase() === 'TRUE';
+        core.debug(`Repo object format sha256 = ${result.repoSHA256}`);
         return result;
     });
 }
diff --git a/src/git-command-manager.ts b/src/git-command-manager.ts
index f5ba40e..d7919b6 100644
--- a/src/git-command-manager.ts
+++ b/src/git-command-manager.ts
@@ -43,7 +43,7 @@ export interface IGitCommandManager {
   getDefaultBranch(repositoryUrl: string): Promise<string>
   getSubmoduleConfigPaths(recursive: boolean): Promise<string[]>
   getWorkingDirectory(): string
-  init(): Promise<void>
+  init(repoSHA256?: boolean): Promise<void>
   isDetached(): Promise<boolean>
   lfsFetch(ref: string): Promise<void>
   lfsInstall(): Promise<void>
@@ -364,8 +364,13 @@ class GitCommandManager {
     return this.workingDirectory
   }
 
-  async init(): Promise<void> {
-    await this.execGit(['init', this.workingDirectory])
+  async init(repoSHA256?: boolean): Promise<void> {
+    const args = ['init']
+    if (repoSHA256) {
+      args.push(`--object-format=sha256`)
+    }
+    args.push(this.workingDirectory)
+    await this.execGit(args)
   }
 
   async isDetached(): Promise<boolean> {
diff --git a/src/git-source-provider.ts b/src/git-source-provider.ts
index ec87178..d4c9a19 100644
--- a/src/git-source-provider.ts
+++ b/src/git-source-provider.ts
@@ -110,7 +110,7 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
       !fsHelper.directoryExistsSync(path.join(settings.repositoryPath, '.git'))
     ) {
       core.startGroup('Initializing the repository')
-      await git.init()
+      await git.init(settings.repoSHA256)
       await git.remoteAdd('origin', repositoryUrl)
       core.endGroup()
     }
diff --git a/src/git-source-settings.ts b/src/git-source-settings.ts
index 4e41ac3..3e08370 100644
--- a/src/git-source-settings.ts
+++ b/src/git-source-settings.ts
@@ -118,4 +118,9 @@ export interface IGitSourceSettings {
    * User override on the GitHub Server/Host URL that hosts the repository to be cloned
    */
   githubServerUrl: string | undefined
+
+  /**
+   * Set Git object format to "sha256" when initializing a Git repository
+   */
+  repoSHA256: boolean
 }
diff --git a/src/input-helper.ts b/src/input-helper.ts
index 059232f..5d64758 100644
--- a/src/input-helper.ts
+++ b/src/input-helper.ts
@@ -161,5 +161,10 @@ export async function getInputs(): Promise<IGitSourceSettings> {
   result.githubServerUrl = core.getInput('github-server-url')
   core.debug(`GitHub Host URL = ${result.githubServerUrl}`)
 
+  // Set Git object format to "sha256" when initializing a Git repository.
+  result.repoSHA256 =
+    (core.getInput('repo-sha256') || 'false').toUpperCase() === 'TRUE'
+  core.debug(`Repo object format sha256 = ${result.repoSHA256}`)
+
   return result
 }