diff --git a/README.md b/README.md
index 9af032f..c222b17 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,8 @@ A [GitHub Action](https://github.com/features/actions) to expose useful environm
 | `CI_BASE_REF`              | Only set for forked repositories / pull request. The branch of the base repository / the base branch name. Copy of `GITHUB_BASE_REF` - for reasons of completeness. | `main`                                |
 | `CI_SHA_SHORT`             | The shortened commit SHA (8 characters) that triggered the workflow.                                                                                           | `ffac537e`                                 |
 | `CI_SHA`                   | The commit SHA that triggered the workflow. Copy of `GITHUB_SHA` - for reasons of completeness.                                                                | `ffac537e6cbbf934b08745a378932722df287a53` |
+| `CI_PR_NUMBER`             | The number of the pull request. Only set for pull requests.                                                                                                    | `42`                                       |
+| `CI_PR_ID`                 | Copy of `CI_PR_NUMBER` for completeness.                                                                                                                       | `42`                                       |
 | `CI_PR_TITLE`              | The title of the pull request. Only set for pull requests.                                                                                                     | `Add feature xyz.`                         |
 | `CI_PR_DESCRIPTION`        | The description of the pull request. Only set for pull requests.                                                                                               | `The feature xyz is the [...]`             |
 | `CI_ACTOR`                 | The name of the person or app that initiated the workflow. Copy of `GITHUB_ACTOR` - for reasons of completeness.                                               | `octocat`                                  |
diff --git a/index.js b/index.js
index 0b5361e..36bbea4 100644
--- a/index.js
+++ b/index.js
@@ -186,6 +186,13 @@ try {
   const pullRequest = github.context.payload &&
       github.context.payload.pull_request;
   if (pullRequest) {
+    const prNumber = pullRequest.number;
+    core.exportVariable('CI_PR_NUMBER', prNumber);
+    core.info(`Set CI_PR_NUMBER=${process.env.CI_PR_NUMBER}`);
+
+    core.exportVariable('CI_PR_ID', prNumber);
+    core.info(`Set CI_PR_ID=${process.env.CI_PR_ID}`);
+
     const prTitle = pullRequest.title;
     core.exportVariable('CI_PR_TITLE', prTitle);
     core.info(`Set CI_PR_TITLE=${process.env.CI_PR_TITLE}`);