diff --git a/Package.swift b/Package.swift
index 6602945..fc79308 100644
--- a/Package.swift
+++ b/Package.swift
@@ -10,7 +10,7 @@ let package = Package(
         .library(name: "HummingbirdCompression", targets: ["HummingbirdCompression"])
     ],
     dependencies: [
-        .package(url: "https://github.com/hummingbird-project/hummingbird.git", from: "2.0.0"),
+        .package(url: "https://github.com/hummingbird-project/hummingbird.git", branch: "non-mutating-response-body-writer"),
         .package(url: "https://github.com/adam-fowler/compress-nio.git", from: "1.4.0"),
         .package(url: "https://github.com/apple/swift-nio.git", from: "2.32.1"),
     ],
diff --git a/Sources/HummingbirdCompression/CompressedBodyWriter.swift b/Sources/HummingbirdCompression/CompressedBodyWriter.swift
index 9548967..fdfd3d2 100644
--- a/Sources/HummingbirdCompression/CompressedBodyWriter.swift
+++ b/Sources/HummingbirdCompression/CompressedBodyWriter.swift
@@ -18,7 +18,7 @@ import Logging
 
 // ResponseBodyWriter that writes a compressed version of the response to a parent writer
 final class CompressedBodyWriter<ParentWriter: ResponseBodyWriter & Sendable>: ResponseBodyWriter {
-    var parentWriter: ParentWriter
+    let parentWriter: ParentWriter
     private let compressor: ZlibCompressor
     private var window: ByteBuffer
     var lastBuffer: ByteBuffer?
diff --git a/Tests/HummingbirdCompressionTests/CompressionTests.swift b/Tests/HummingbirdCompressionTests/CompressionTests.swift
index d22ceb1..e31d6d0 100644
--- a/Tests/HummingbirdCompressionTests/CompressionTests.swift
+++ b/Tests/HummingbirdCompressionTests/CompressionTests.swift
@@ -140,11 +140,16 @@ class HummingBirdCompressionTests: XCTestCase {
         struct VerifyResponseBodyChunkSize<Context: RequestContext>: RouterMiddleware {
             let bufferSize: Int
 
-            struct Writer: ResponseBodyWriter {
-                var parentWriter: any ResponseBodyWriter
+            final class Writer: ResponseBodyWriter {
+                let parentWriter: any ResponseBodyWriter
                 let bufferSize: Int
 
-                mutating func write(_ buffer: ByteBuffer) async throws {
+                init(parentWriter: any ResponseBodyWriter, bufferSize: Int) {
+                    self.parentWriter = parentWriter
+                    self.bufferSize = bufferSize
+                }
+
+                func write(_ buffer: ByteBuffer) async throws {
                     XCTAssertLessThanOrEqual(buffer.capacity, self.bufferSize)
                     try await self.parentWriter.write(buffer)
                 }