diff --git a/Package.resolved b/Package.resolved
index 34d1d759c..483a74faa 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -50,8 +50,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/swiftlang/swift-syntax.git",
       "state" : {
-        "revision" : "e9b514360b46276ea54e535fddf4cb1ae2942c44",
-        "version" : "604.0.0-prerelease-2026-03-31"
+        "revision" : "51c8c237beea1baa9cac64ef83cec68c6790506c",
+        "version" : "604.0.0-prerelease-2026-04-21"
       }
     },
     {
diff --git a/Package.swift b/Package.swift
index e63430c0c..483c49efc 100644
--- a/Package.swift
+++ b/Package.swift
@@ -36,7 +36,7 @@ let package = Package(
     ],
     dependencies: [
         .package(url: "https://github.com/apple/swift-argument-parser.git", .upToNextMajor(from: "1.6.1")),
-        .package(url: "https://github.com/swiftlang/swift-syntax.git", exact: "604.0.0-prerelease-2026-03-31"),
+        .package(url: "https://github.com/swiftlang/swift-syntax.git", exact: "604.0.0-prerelease-2026-04-21"),
         .package(url: "https://github.com/jpsim/SourceKitten.git", .upToNextMajor(from: "0.37.2")),
         .package(url: "https://github.com/jpsim/Yams.git", .upToNextMajor(from: "6.0.2")),
         .package(url: "https://github.com/scottrhoyt/SwiftyTextTable.git", .upToNextMajor(from: "0.9.0")),
diff --git a/bazel/repos.bzl b/bazel/repos.bzl
index 4bafd5a98..f86df2dff 100644
--- a/bazel/repos.bzl
+++ b/bazel/repos.bzl
@@ -35,9 +35,9 @@ def swiftlint_repos(bzlmod = False):
 
     http_archive(
         name = "SwiftSyntax",
-        sha256 = "b058323416a5d7a6fb88040393980dd4da2454586136776cd8cf3d16aa171132",
-        strip_prefix = "swift-syntax-604.0.0-prerelease-2026-03-31",
-        url = "https://github.com/swiftlang/swift-syntax/archive/refs/tags/604.0.0-prerelease-2026-03-31.tar.gz",
+        sha256 = "39b3c675e5f21c40ef7e74f2b94c20df22c609ef282b9c16ce15937e390ed6ac",
+        strip_prefix = "swift-syntax-604.0.0-prerelease-2026-04-21",
+        url = "https://github.com/swiftlang/swift-syntax/archive/refs/tags/604.0.0-prerelease-2026-04-21.tar.gz",
     )
 
     http_archive(