diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4a9a3f77..f090e6f2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,8 @@
 
 ## Master
 
+- Add `.xctestplan` extension to available file extensions [@gsl-anthonymerle][] - [#653](https://github.com/danger/swift/pull/653)
+
 ## 3.21.2
 
 - Fix Runner's path resolution to enable `--cwd` with relative paths [@Fab1n](https://github.com/Fab1n) - [#650](https://github.com/danger/swift/pull/650)
@@ -622,4 +624,5 @@ This release also includes:
 [@aserdobintsev]: https://github.com/aserdobintsev
 [@dromerobarria]: https://github.com/dromerobarria
 [@msnazarow]: https://github.com/msnazarow
-[@Davarg]https://github.com/Davarg
+[@Davarg]: https://github.com/Davarg
+[@gsl-anthonymerle]: https://github.com/gsl-anthonymerle
diff --git a/Sources/Danger/File.swift b/Sources/Danger/File.swift
index 733e98ec..67740898 100644
--- a/Sources/Danger/File.swift
+++ b/Sources/Danger/File.swift
@@ -19,7 +19,7 @@ public extension File {
 
 public enum FileType: String, Equatable, CaseIterable {
     // swiftlint:disable:next identifier_name
-    case h, json, m, markdown = "md", mm, pbxproj, plist, storyboard, swift, xcscheme, yaml, yml
+    case h, json, m, markdown = "md", mm, pbxproj, plist, storyboard, swift, xcscheme, yaml, yml, xctestplan
 }
 
 // MARK: - FileType extensions
diff --git a/Tests/DangerTests/FileTests.swift b/Tests/DangerTests/FileTests.swift
index b58f5fed..788e7880 100644
--- a/Tests/DangerTests/FileTests.swift
+++ b/Tests/DangerTests/FileTests.swift
@@ -129,4 +129,12 @@ final class FileTests: XCTestCase {
 
         XCTAssertEqual(file.fileType, expectedType)
     }
+
+    func test_fileType_forXCTestPlan() {
+        let file: File = "TestPlan.xctestplan"
+
+        let expectedType: FileType = .xctestplan
+
+        XCTAssertEqual(file.fileType, expectedType)
+    }
 }