diff --git a/action.yml b/action.yml
index fb67ceb..19a4173 100644
--- a/action.yml
+++ b/action.yml
@@ -5,9 +5,9 @@ branding:
   color: "blue"
 inputs:
   branch:
-    description: "The branch name"
+    description: "Set to specify a specific branch, default is the current HEAD"
     required: true
-    default: "master"
+    default: "HEAD"
   tag_prefix:
     description: "The prefix to use to identify tags"
     required: false
diff --git a/dist/index.js b/dist/index.js
index 044ada7..13419e9 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1072,6 +1072,10 @@ const setOutput = (major, minor, patch, increment, changed, branch, namespace) =
     tag = `${tagPrefix}${major}`;
   }
 
+  if (namespace !== '') {
+    tag += `-${namespace}`
+  }
+
   const repository = process.env.GITHUB_REPOSITORY;
 
   if (!changed) {
@@ -1130,11 +1134,15 @@ async function run() {
     const remoteExists = remote !== '';
     const remotePrefix = remoteExists ? 'origin/' : '';
 
-    const branch = `${remotePrefix}${core.getInput('branch', { required: true })}`;
+    let branch = `${remotePrefix}${core.getInput('branch', { required: true })}`;
     const majorPattern = createMatchTest(core.getInput('major_pattern', { required: true }));
     const minorPattern = createMatchTest(core.getInput('minor_pattern', { required: true }));
     const changePath = core.getInput('change_path') || '';
 
+    if (branch === 'HEAD') {
+      branch = (await cmd('git', 'rev-parse', 'HEAD')).trim();
+    }
+
     const versionPattern = shortTags ? '*[0-9.]' : '[0-9]+\\.[0-9]+\\.[0-9]+'
     const releasePattern = namespace === '' ? `${tagPrefix}${versionPattern}` : `${tagPrefix}${versionPattern}-${namespace}`;
     let major = 0, minor = 0, patch = 0, increment = 0;
diff --git a/index.js b/index.js
index 1acd438..34ddeb0 100644
--- a/index.js
+++ b/index.js
@@ -113,11 +113,15 @@ async function run() {
     const remoteExists = remote !== '';
     const remotePrefix = remoteExists ? 'origin/' : '';
 
-    const branch = `${remotePrefix}${core.getInput('branch', { required: true })}`;
+    let branch = `${remotePrefix}${core.getInput('branch', { required: true })}`;
     const majorPattern = createMatchTest(core.getInput('major_pattern', { required: true }));
     const minorPattern = createMatchTest(core.getInput('minor_pattern', { required: true }));
     const changePath = core.getInput('change_path') || '';
 
+    if (branch === 'HEAD') {
+      branch = (await cmd('git', 'rev-parse', 'HEAD')).trim();
+    }
+
     const versionPattern = shortTags ? '*[0-9.]' : '[0-9]+\\.[0-9]+\\.[0-9]+'
     const releasePattern = namespace === '' ? `${tagPrefix}${versionPattern}` : `${tagPrefix}${versionPattern}-${namespace}`;
     let major = 0, minor = 0, patch = 0, increment = 0;
diff --git a/index.test.js b/index.test.js
index 63f2717..a922661 100644
--- a/index.test.js
+++ b/index.test.js
@@ -85,6 +85,22 @@ test('Repository with commits shows increment', () => {
     repo.clean();
 });
 
+test('Repository show commit for checked out commit', () => {
+    const repo = createTestRepo({ branch: 'HEAD' }); // 0.0.0+0
+
+    repo.makeCommit('Initial Commit'); // 0.0.1+0
+    repo.makeCommit(`Second Commit`); // 0.0.1+1
+    let result = repo.runAction();
+    expect(result).toMatch('Version is 0.0.1+1');
+
+    repo.exec(`git checkout HEAD~1`); // 0.0.1+1
+    result = repo.runAction();
+    expect(result).toMatch('Version is 0.0.1+0');
+
+
+    repo.clean();
+});
+
 test('Tagging does not break version', () => {
     const repo = createTestRepo(); // 0.0.0+0