diff --git a/.github/workflows/triage.yaml b/.github/workflows/triage.yaml
index 0cbdbbc..b5f26ba 100644
--- a/.github/workflows/triage.yaml
+++ b/.github/workflows/triage.yaml
@@ -15,37 +15,6 @@ jobs:
 
     steps:
       - name: "Add labels based on branch name"
-        uses: "actions/github-script@v5"
+        uses: "./.github/actions/github/pull-request/add-label-based-on-branch-name"
         with:
           github-token: "${{ secrets.ERGEBNIS_BOT_TOKEN }}"
-          script: |
-            const branchPrefixLabels = {
-              feature: "enhancement",
-              fix: "bug",
-            };
-
-            const pullRequest = context.payload.pull_request;
-            const repository = context.repo;
-
-            const branchName = pullRequest.head.ref;
-
-            const matches = branchName.match(new RegExp('^([^/]+)\/'));;
-
-            if (!matches instanceof Array) {
-              return;
-            }
-
-            if (!branchPrefixLabels.hasOwnProperty(matches[1])) {
-              return;
-            }
-
-            const label = branchPrefixLabels[matches[1]];
-
-            github.rest.issues.addLabels({
-              issue_number: pullRequest.number,
-              labels: [
-                label,
-              ],
-              owner: repository.owner,
-              repo: repository.repo,
-            });
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 69c15c8..962a497 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ For a full diff see [`1.2.1...main`][1.2.1...main].
 - Added composite action `github/add-assignee-to-pull-request` ([#59]), by [@localheinz]
 - Added composite action `github/approve-pull-request` ([#60]), by [@localheinz]
 - Added composite action `github/merge-pull-request` ([#64]), by [@localheinz]
+- Added composite action `github/pull-request/add-label-based-on-branch-name` ([#67]), by [@localheinz]
 
 ## [`1.2.1`][1.2.1]
 
@@ -64,5 +65,6 @@ For a full diff see [`1.0.0...main`][1.0.0...main].
 [#59]: https://github.com/ergebnis/.github/pull/59
 [#60]: https://github.com/ergebnis/.github/pull/60
 [#64]: https://github.com/ergebnis/.github/pull/64
+[#67]: https://github.com/ergebnis/.github/pull/67
 
 [@localheinz]: https://github.com/localheinz
diff --git a/actions/github/pull-request/add-label-based-on-branch-name/action.yaml b/actions/github/pull-request/add-label-based-on-branch-name/action.yaml
new file mode 100644
index 0000000..09feac7
--- /dev/null
+++ b/actions/github/pull-request/add-label-based-on-branch-name/action.yaml
@@ -0,0 +1,79 @@
+# https://docs.github.com/en/actions/creating-actions/creating-a-composite-action
+# https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#inputs
+# https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#runs-for-composite-run-steps-actions
+# https://docs.github.com/en/rest/reference/issues#add-labels-to-an-issue
+# https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#pull_request
+# https://docs.github.com/en/developers/webhooks-and-events/webhooks/webhook-events-and-payloads#workflow_run
+
+name: "Add label to pull request based on branch name"
+
+description: "Adds a label to a pull request based on the branch name"
+
+inputs:
+  github-token:
+    description: "GitHub token of a user with permission to add labels to to a pull request"
+    required: true
+
+runs:
+  using: "composite"
+
+  steps:
+    - name: "Determine pull request number"
+      uses: "actions/github-script@v5"
+      with:
+        github-token: "${{ inputs.github-token }}"
+        script: |
+          if (
+            context.eventName == 'pull_request' ||
+            context.eventName == 'pull_request_target'
+          ) {
+            core.exportVariable("PULL_REQUEST_NUMBER", context.payload.pull_request.number);
+            core.exportVariable("PULL_REQUEST_BRANCH_NAME", context.payload.pull_request.head.ref);
+
+            return;
+          }
+
+          core.setFailed(`Unable to determine the pull request number and branch name for event "${context.eventName}"`);
+
+    - name: "Add label to pull request based on branch name"
+      uses: "actions/github-script@v5"
+      with:
+        github-token: "${{ inputs.github-token }}"
+        script: |
+          if (!process.env.PULL_REQUEST_NUMBER) {
+            core.setFailed("The environment variable PULL_REQUEST_NUMBER is not defined.");
+
+            return;
+          }
+
+          if (!process.env.PULL_REQUEST_BRANCH_NAME) {
+            core.setFailed("The environment variable PULL_REQUEST_BRANCH_NAME is not defined.");
+
+            return;
+          }
+
+          const branchPrefixToLabel = {
+            feature: "enhancement",
+            fix: "bug",
+          };
+
+          const matches = process.env.PULL_REQUEST_BRANCH_NAME.match(new RegExp('^([^/]+)\/'));
+
+          if (!matches instanceof Array) {
+            return;
+          }
+
+          if (!branchPrefixToLabel.hasOwnProperty(matches[1])) {
+            return;
+          }
+
+          const label = branchPrefixToLabel[matches[1]];
+
+          github.rest.issues.addLabels({
+            issue_number: process.env.PULL_REQUEST_NUMBER,
+            labels: [
+              label,
+            ],
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+          });