diff --git a/README.md b/README.md
index c344e98..b2b8329 100644
--- a/README.md
+++ b/README.md
@@ -29,6 +29,11 @@ don't allow this because they don't work on a level of individual jobs or steps.
   - The `base` input parameter must not be the same as the branch that triggered the workflow
   - Changes are detected against the merge-base with the configured base branch or the default branch
   - Uses git commands to detect changes - repository must be already [checked out](https://github.com/actions/checkout)
+- **[Merge queue](https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/configuring-pull-request-merges/managing-a-merge-queue):**
+  - Workflow triggered by **[merge_group](https://docs.github.com/en/actions/reference/events-that-trigger-workflows#merge_group)**
+  - The `base` and `ref` input parameters default to commit hashes from the event
+    unless explicitly specified.
+  - Uses git commands to detect changes - repository must be already [checked out](https://github.com/actions/checkout)
 - **Master, Release, or other long-lived branches:**
   - Workflow triggered by **[push](https://docs.github.com/en/actions/reference/events-that-trigger-workflows#push)** event
   when `base` input parameter is the same as the branch that triggered the workflow:
@@ -48,7 +53,7 @@ don't allow this because they don't work on a level of individual jobs or steps.
 ## Example
 
 ```yaml
-- uses: step-security/paths-filter@v3
+- uses: step-security/paths-filter@v4
   id: changes
   with:
     filters: |
@@ -74,7 +79,7 @@ For more scenarios see [examples](#examples) section.
 
 ## What's New
 
-- New major release `v3` after update to Node 20 [Breaking change]
+- New major release `v4` after update to Node 24 [Breaking change]
 - Add `ref` input parameter
 - Add `list-files: csv` format
 - Configure matrix job to run for each folder with changes using `changes` output
@@ -84,7 +89,7 @@ For more scenarios see [examples](#examples) section.
 ## Usage
 
 ```yaml
-- uses: step-security/paths-filter@v3
+- uses: step-security/paths-filter@v4
   with:
     # Defines filters applied to detected changed files.
     # Each filter has a name and a list of rules.
@@ -104,6 +109,8 @@ For more scenarios see [examples](#examples) section.
     # Branch, tag, or commit SHA against which the changes will be detected.
     # If it references the same branch it was pushed to,
     # changes are detected against the most recent commit before the push.
+    # If it is empty and action is triggered by merge_group event,
+    # the base commit in the event will be used.
     # Otherwise, it uses git merge-base to find the best common ancestor between
     # current branch (HEAD) and base.
     # When merge-base is found, it's used for change detection - only changes
@@ -117,6 +124,8 @@ For more scenarios see [examples](#examples) section.
     # Git reference (e.g. branch name) from which the changes will be detected.
     # Useful when workflow can be triggered only on the default branch (e.g. repository_dispatch event)
     # but you want to get changes on a different branch.
+    # If this is empty and action is triggered by merge_group event,
+    # the head commit in the event will be used.
     # This option is ignored if action is triggered by pull_request event.
     # default: ${{ github.ref }}
     ref:
@@ -154,14 +163,14 @@ For more scenarios see [examples](#examples) section.
     # Default: ${{ github.token }}
     token: ''
 
-    # Optional parameter to override the default behavior of file matching algorithm. 
+    # Optional parameter to override the default behavior of file matching algorithm.
     # By default files that match at least one pattern defined by the filters will be included.
     # This parameter allows to override the "at least one pattern" behavior to make it so that
-    # all of the patterns have to match or otherwise the file is excluded. 
-    # An example scenario where this is useful if you would like to match all 
-    # .ts files in a sub-directory but not .md files. 
-    # The filters below will match markdown files despite the exclusion syntax UNLESS 
-    # you specify 'every' as the predicate-quantifier parameter. When you do that, 
+    # all of the patterns have to match or otherwise the file is excluded.
+    # An example scenario where this is useful if you would like to match all
+    # .ts files in a sub-directory but not .md files.
+    # The filters below will match markdown files despite the exclusion syntax UNLESS
+    # you specify 'every' as the predicate-quantifier parameter. When you do that,
     # it will only match the .ts files in the subdirectory as expected.
     #
     # backend:
@@ -192,8 +201,8 @@ jobs:
   tests:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: step-security/paths-filter@v3
+    - uses: actions/checkout@v6
+    - uses: step-security/paths-filter@v4
       id: filter
       with:
         filters: |
@@ -237,7 +246,7 @@ jobs:
       frontend: ${{ steps.filter.outputs.frontend }}
     steps:
     # For pull requests it's not necessary to checkout the code
-    - uses: step-security/paths-filter@v3
+    - uses: step-security/paths-filter@v4
       id: filter
       with:
         filters: |
@@ -252,7 +261,7 @@ jobs:
     if: ${{ needs.changes.outputs.backend == 'true' }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - ...
 
   # JOB to build and test frontend code
@@ -261,7 +270,7 @@ jobs:
     if: ${{ needs.changes.outputs.frontend == 'true' }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - ...
 ```
 
@@ -283,7 +292,7 @@ jobs:
       packages: ${{ steps.filter.outputs.changes }}
     steps:
     # For pull requests it's not necessary to checkout the code
-    - uses: step-security/paths-filter@v3
+    - uses: step-security/paths-filter@v4
       id: filter
       with:
         filters: |
@@ -300,7 +309,7 @@ jobs:
         package: ${{ fromJSON(needs.changes.outputs.packages) }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - ...
 ```
 
@@ -317,6 +326,12 @@ on:
     branches: # PRs to the following branches will trigger the workflow
       - master
       - develop
+  # Optionally you can use the action in the merge queue
+  # if your repository enables the feature.
+  merge_group:
+    branches:
+      - master
+      - develop
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -324,8 +339,8 @@ jobs:
     permissions:
       pull-requests: read
     steps:
-    - uses: actions/checkout@v4
-    - uses: step-security/paths-filter@v3
+    - uses: actions/checkout@v6
+    - uses: step-security/paths-filter@v4
       id: filter
       with:
         filters: ... # Configure your filters
@@ -345,12 +360,12 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         # This may save additional git fetch roundtrip if
         # merge-base is found within latest 20 commits
         fetch-depth: 20
-    - uses: step-security/paths-filter@v3
+    - uses: step-security/paths-filter@v4
       id: filter
       with:
         base: develop # Change detection against merge-base with this branch
@@ -373,8 +388,8 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - uses: step-security/paths-filter@v3
+    - uses: actions/checkout@v6
+    - uses: step-security/paths-filter@v4
       id: filter
       with:
         # Use context to get the branch where commits were pushed.
@@ -401,14 +416,14 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
 
       # Some action that modifies files tracked by git (e.g. code linter)
     - uses: johndoe/some-action@v1
 
       # Filter to detect which files were modified
       # Changes could be, for example, automatically committed
-    - uses: step-security/paths-filter@v3
+    - uses: step-security/paths-filter@v4
       id: filter
       with:
         base: HEAD
@@ -423,7 +438,7 @@ jobs:
   <summary>Define filter rules in own file</summary>
 
 ```yaml
-- uses: step-security/paths-filter@v3
+- uses: step-security/paths-filter@v4
       id: filter
       with:
         # Path to file where filters are defined
@@ -436,7 +451,7 @@ jobs:
   <summary>Use YAML anchors to reuse path expression(s) inside another rule</summary>
 
 ```yaml
-- uses: step-security/paths-filter@v3
+- uses: step-security/paths-filter@v4
       id: filter
       with:
         # &shared is YAML anchor,
@@ -457,7 +472,7 @@ jobs:
   <summary>Consider if file was added, modified or deleted</summary>
 
 ```yaml
-- uses: step-security/paths-filter@v3
+- uses: step-security/paths-filter@v4
       id: filter
       with:
         # Changed file can be 'added', 'modified', or 'deleted'.
@@ -483,7 +498,7 @@ jobs:
   <summary>Detect changes in folder only for some file extensions</summary>
 
 ```yaml
-- uses: step-security/paths-filter@v3
+- uses: step-security/paths-filter@v4
       id: filter
       with:
         # This makes it so that all the patterns have to match a file for it to be
@@ -511,7 +526,7 @@ jobs:
   <summary>Passing list of modified files as command line args in Linux shell</summary>
 
 ```yaml
-- uses: step-security/paths-filter@v3
+- uses: step-security/paths-filter@v4
   id: filter
   with:
     # Enable listing of files matching each filter.
@@ -537,7 +552,7 @@ jobs:
   <summary>Passing list of modified files as JSON array to another action</summary>
 
 ```yaml
-- uses: step-security/paths-filter@v3
+- uses: step-security/paths-filter@v4
   id: filter
   with:
     # Enable listing of files matching each filter.
@@ -557,4 +572,3 @@ jobs:
 ```
 
 </details>
-
diff --git a/dist/index.js b/dist/index.js
index 0c24361..c166525 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -635,33 +635,49 @@ async function getChangedFiles(token, base, ref, initialFetchDepth) {
         }
         return await git.getChangesOnHead();
     }
-    const prEvents = ['pull_request', 'pull_request_review', 'pull_request_review_comment', 'pull_request_target'];
-    if (prEvents.includes(github.context.eventName)) {
-        if (ref) {
-            core.warning(`'ref' input parameter is ignored when 'base' is set to HEAD`);
-        }
-        if (base) {
-            core.warning(`'base' input parameter is ignored when action is triggered by pull request event`);
-        }
-        const pr = github.context.payload.pull_request;
-        if (token) {
-            return await getChangedFilesFromApi(token, pr);
-        }
-        if (github.context.eventName === 'pull_request_target') {
-            // pull_request_target is executed in context of base branch and GITHUB_SHA points to last commit in base branch
-            // Therefor it's not possible to look at changes in last commit
-            // At the same time we don't want to fetch any code from forked repository
-            throw new Error(`'token' input parameter is required if action is triggered by 'pull_request_target' event`);
+    switch (github.context.eventName) {
+        // To keep backward compatibility, commits in GitHub pull request event
+        // take precedence over manual inputs.
+        case 'pull_request':
+        case 'pull_request_review':
+        case 'pull_request_review_comment':
+        case 'pull_request_target': {
+            if (ref) {
+                core.warning(`'ref' input parameter is ignored when 'base' is set to HEAD`);
+            }
+            if (base) {
+                core.warning(`'base' input parameter is ignored when action is triggered by pull request event`);
+            }
+            const pr = github.context.payload.pull_request;
+            if (token) {
+                return await getChangedFilesFromApi(token, pr);
+            }
+            if (github.context.eventName === 'pull_request_target') {
+                // pull_request_target is executed in context of base branch and GITHUB_SHA points to last commit in base branch
+                // Therefore it's not possible to look at changes in last commit
+                // At the same time we don't want to fetch any code from forked repository
+                throw new Error(`'token' input parameter is required if action is triggered by 'pull_request_target' event`);
+            }
+            core.info('Github token is not available - changes will be detected using git diff');
+            const baseSha = (_a = github.context.payload.pull_request) === null || _a === void 0 ? void 0 : _a.base.sha;
+            const defaultBranch = (_b = github.context.payload.repository) === null || _b === void 0 ? void 0 : _b.default_branch;
+            const currentRef = await git.getCurrentRef();
+            return await git.getChanges(base || baseSha || defaultBranch, currentRef);
+        }
+        // To keep backward compatibility, manual inputs take precedence over
+        // commits in GitHub merge queue event.
+        case 'merge_group': {
+            const mergeGroup = github.context.payload;
+            if (!base) {
+                base = mergeGroup.merge_group.base_sha;
+            }
+            if (!ref) {
+                ref = mergeGroup.merge_group.head_sha;
+            }
+            break;
         }
-        core.info('Github token is not available - changes will be detected using git diff');
-        const baseSha = (_a = github.context.payload.pull_request) === null || _a === void 0 ? void 0 : _a.base.sha;
-        const defaultBranch = (_b = github.context.payload.repository) === null || _b === void 0 ? void 0 : _b.default_branch;
-        const currentRef = await git.getCurrentRef();
-        return await git.getChanges(base || baseSha || defaultBranch, currentRef);
-    }
-    else {
-        return getChangedFilesFromGit(base, ref, initialFetchDepth);
     }
+    return getChangedFilesFromGit(base, ref, initialFetchDepth);
 }
 async function getChangedFilesFromGit(base, head, initialFetchDepth) {
     var _a;
diff --git a/src/main.ts b/src/main.ts
index 2e636a3..60e26e5 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -2,7 +2,7 @@ import * as fs from 'fs'
 import * as core from '@actions/core'
 import * as github from '@actions/github'
 import {GetResponseDataTypeFromEndpointMethod} from '@octokit/types'
-import {PushEvent, PullRequestEvent} from '@octokit/webhooks-types'
+import {MergeGroupEvent, PullRequest, PushEvent} from '@octokit/webhooks-types'
 import axios, {isAxiosError} from 'axios'
 
 import {
@@ -101,32 +101,50 @@ async function getChangedFiles(token: string, base: string, ref: string, initial
     return await git.getChangesOnHead()
   }
 
-  const prEvents = ['pull_request', 'pull_request_review', 'pull_request_review_comment', 'pull_request_target']
-  if (prEvents.includes(github.context.eventName)) {
-    if (ref) {
-      core.warning(`'ref' input parameter is ignored when 'base' is set to HEAD`)
-    }
-    if (base) {
-      core.warning(`'base' input parameter is ignored when action is triggered by pull request event`)
-    }
-    const pr = github.context.payload.pull_request as PullRequestEvent
-    if (token) {
-      return await getChangedFilesFromApi(token, pr)
+  switch (github.context.eventName) {
+    // To keep backward compatibility, commits in GitHub pull request event
+    // take precedence over manual inputs.
+    case 'pull_request':
+    case 'pull_request_review':
+    case 'pull_request_review_comment':
+    case 'pull_request_target': {
+      if (ref) {
+        core.warning(`'ref' input parameter is ignored when 'base' is set to HEAD`)
+      }
+      if (base) {
+        core.warning(`'base' input parameter is ignored when action is triggered by pull request event`)
+      }
+      const pr = github.context.payload.pull_request as PullRequest
+      if (token) {
+        return await getChangedFilesFromApi(token, pr)
+      }
+      if (github.context.eventName === 'pull_request_target') {
+        // pull_request_target is executed in context of base branch and GITHUB_SHA points to last commit in base branch
+        // Therefore it's not possible to look at changes in last commit
+        // At the same time we don't want to fetch any code from forked repository
+        throw new Error(`'token' input parameter is required if action is triggered by 'pull_request_target' event`)
+      }
+      core.info('Github token is not available - changes will be detected using git diff')
+      const baseSha = github.context.payload.pull_request?.base.sha
+      const defaultBranch = github.context.payload.repository?.default_branch
+      const currentRef = await git.getCurrentRef()
+      return await git.getChanges(base || baseSha || defaultBranch, currentRef)
     }
-    if (github.context.eventName === 'pull_request_target') {
-      // pull_request_target is executed in context of base branch and GITHUB_SHA points to last commit in base branch
-      // Therefor it's not possible to look at changes in last commit
-      // At the same time we don't want to fetch any code from forked repository
-      throw new Error(`'token' input parameter is required if action is triggered by 'pull_request_target' event`)
+    // To keep backward compatibility, manual inputs take precedence over
+    // commits in GitHub merge queue event.
+    case 'merge_group': {
+      const mergeGroup = github.context.payload as MergeGroupEvent
+      if (!base) {
+        base = mergeGroup.merge_group.base_sha
+      }
+      if (!ref) {
+        ref = mergeGroup.merge_group.head_sha
+      }
+      break
     }
-    core.info('Github token is not available - changes will be detected using git diff')
-    const baseSha = github.context.payload.pull_request?.base.sha
-    const defaultBranch = github.context.payload.repository?.default_branch
-    const currentRef = await git.getCurrentRef()
-    return await git.getChanges(base || baseSha || defaultBranch, currentRef)
-  } else {
-    return getChangedFilesFromGit(base, ref, initialFetchDepth)
   }
+
+  return getChangedFilesFromGit(base, ref, initialFetchDepth)
 }
 
 async function getChangedFilesFromGit(base: string, head: string, initialFetchDepth: number): Promise<File[]> {
@@ -192,7 +210,7 @@ async function getChangedFilesFromGit(base: string, head: string, initialFetchDe
 }
 
 // Uses github REST api to get list of files changed in PR
-async function getChangedFilesFromApi(token: string, pullRequest: PullRequestEvent): Promise<File[]> {
+async function getChangedFilesFromApi(token: string, pullRequest: PullRequest): Promise<File[]> {
   core.startGroup(`Fetching list of changed files for PR#${pullRequest.number} from Github API`)
   try {
     const client = github.getOctokit(token)