diff --git a/Tests/AsyncHTTPClientTests/HTTP2ClientTests+XCTest.swift b/Tests/AsyncHTTPClientTests/HTTP2ClientTests+XCTest.swift
index ffe9c14a1..753cf9e37 100644
--- a/Tests/AsyncHTTPClientTests/HTTP2ClientTests+XCTest.swift
+++ b/Tests/AsyncHTTPClientTests/HTTP2ClientTests+XCTest.swift
@@ -29,6 +29,10 @@ extension HTTP2ClientTests {
             ("testConcurrentRequests", testConcurrentRequests),
             ("testConcurrentRequestsFromDifferentThreads", testConcurrentRequestsFromDifferentThreads),
             ("testConcurrentRequestsWorkWithRequiredEventLoop", testConcurrentRequestsWorkWithRequiredEventLoop),
+            ("testUncleanShutdownCancelsExecutingAndQueuedTasks", testUncleanShutdownCancelsExecutingAndQueuedTasks),
+            ("testCancelingRunningRequest", testCancelingRunningRequest),
+            ("testStressCancelingRunningRequestFromDifferentThreads", testStressCancelingRunningRequestFromDifferentThreads),
+            ("testPlatformConnectErrorIsForwardedOnTimeout", testPlatformConnectErrorIsForwardedOnTimeout),
         ]
     }
 }
diff --git a/Tests/AsyncHTTPClientTests/HTTP2ClientTests.swift b/Tests/AsyncHTTPClientTests/HTTP2ClientTests.swift
index bef964577..34076f75c 100644
--- a/Tests/AsyncHTTPClientTests/HTTP2ClientTests.swift
+++ b/Tests/AsyncHTTPClientTests/HTTP2ClientTests.swift
@@ -19,16 +19,19 @@
 #endif
 import Logging
 import NIOCore
+import NIOHTTP1
 import NIOPosix
 import NIOSSL
 import XCTest
 
 class HTTP2ClientTests: XCTestCase {
-    func makeDefaultHTTPClient() -> HTTPClient {
+    func makeDefaultHTTPClient(
+        eventLoopGroupProvider: HTTPClient.EventLoopGroupProvider = .createNew
+    ) -> HTTPClient {
         var tlsConfig = TLSConfiguration.makeClientConfiguration()
         tlsConfig.certificateVerification = .none
         return HTTPClient(
-            eventLoopGroupProvider: .createNew,
+            eventLoopGroupProvider: eventLoopGroupProvider,
             configuration: HTTPClient.Configuration(
                 tlsConfiguration: tlsConfig,
                 httpVersion: .automatic
@@ -37,6 +40,18 @@ class HTTP2ClientTests: XCTestCase {
         )
     }
 
+    func makeClientWithActiveHTTP2Connection<RequestHandler>(
+        to bin: HTTPBin<RequestHandler>,
+        eventLoopGroupProvider: HTTPClient.EventLoopGroupProvider = .createNew
+    ) -> HTTPClient {
+        let client = self.makeDefaultHTTPClient(eventLoopGroupProvider: eventLoopGroupProvider)
+        var response: HTTPClient.Response?
+        XCTAssertNoThrow(response = try client.get(url: "https://localhost:\(bin.port)/get").wait())
+        XCTAssertEqual(.ok, response?.status)
+        XCTAssertEqual(response?.version, .http2)
+        return client
+    }
+
     func testSimpleGet() {
         let bin = HTTPBin(.http2(compress: false))
         defer { XCTAssertNoThrow(try bin.shutdown()) }
@@ -92,7 +107,7 @@ class HTTP2ClientTests: XCTestCase {
 
                     for _ in 0..<numberOfRequestsPerWorkers {
                         var response: HTTPClient.Response?
-                        XCTAssertNoThrow(response = try client.get(url: url).wait())
+                        XCTAssertNoThrow(response = try client.get(url: "https://localhost:\(bin.port)/get").wait())
 
                         XCTAssertEqual(.ok, response?.status)
                         XCTAssertEqual(response?.version, .http2)
@@ -187,4 +202,193 @@ class HTTP2ClientTests: XCTestCase {
         // all workers should be running, let's wait for them to finish
         allDone.wait()
     }
+
+    func testUncleanShutdownCancelsExecutingAndQueuedTasks() {
+        let bin = HTTPBin(.http2(compress: false))
+        defer { XCTAssertNoThrow(try bin.shutdown()) }
+        let clientGroup = MultiThreadedEventLoopGroup(numberOfThreads: 1)
+        defer { XCTAssertNoThrow(try clientGroup.syncShutdownGracefully()) }
+        // we need an active connection to guarantee that requests are executed immediately
+        // without waiting for connection establishment
+        let client = self.makeClientWithActiveHTTP2Connection(to: bin, eventLoopGroupProvider: .shared(clientGroup))
+
+        // start 20 requests which are guaranteed to never get any response
+        // 10 of them will executed and the other 10 will be queued
+        // because HTTPBin has a default `maxConcurrentStreams` limit of 10
+        let responses = (0..<20).map { _ in
+            client.get(url: "https://localhost:\(bin.port)/wait")
+        }
+
+        XCTAssertNoThrow(try client.syncShutdown())
+
+        var results: [Result<HTTPClient.Response, Error>] = []
+        XCTAssertNoThrow(results = try EventLoopFuture
+            .whenAllComplete(responses, on: clientGroup.next())
+            .timeout(after: .seconds(2))
+            .wait())
+
+        for result in results {
+            switch result {
+            case .success:
+                XCTFail("Shouldn't succeed")
+            case .failure(let error):
+                XCTAssertEqual(error as? HTTPClientError, .cancelled)
+            }
+        }
+    }
+
+    func testCancelingRunningRequest() {
+        let bin = HTTPBin(.http2(compress: false)) { _ in SendHeaderAndWaitChannelHandler() }
+        defer { XCTAssertNoThrow(try bin.shutdown()) }
+        let client = self.makeDefaultHTTPClient()
+        defer { XCTAssertNoThrow(try client.syncShutdown()) }
+
+        var maybeRequest: HTTPClient.Request?
+        XCTAssertNoThrow(maybeRequest = try HTTPClient.Request(url: "https://localhost:\(bin.port)"))
+        guard let request = maybeRequest else { return }
+
+        var task: HTTPClient.Task<Void>!
+        let delegate = HeadReceivedCallback { _ in
+            // request is definitely running because we just received a head from the server
+            task.cancel()
+        }
+        task = client.execute(
+            request: request,
+            delegate: delegate
+        )
+
+        XCTAssertThrowsError(try task.futureResult.timeout(after: .seconds(2)).wait()) {
+            XCTAssertEqual($0 as? HTTPClientError, .cancelled)
+        }
+    }
+
+    func testStressCancelingRunningRequestFromDifferentThreads() {
+        let bin = HTTPBin(.http2(compress: false)) { _ in SendHeaderAndWaitChannelHandler() }
+        defer { XCTAssertNoThrow(try bin.shutdown()) }
+        let client = self.makeDefaultHTTPClient()
+        defer { XCTAssertNoThrow(try client.syncShutdown()) }
+        let cancelPool = MultiThreadedEventLoopGroup(numberOfThreads: 10)
+        defer { XCTAssertNoThrow(try cancelPool.syncShutdownGracefully()) }
+
+        var maybeRequest: HTTPClient.Request?
+        XCTAssertNoThrow(maybeRequest = try HTTPClient.Request(url: "https://localhost:\(bin.port)"))
+        guard let request = maybeRequest else { return }
+
+        let tasks = (0..<100).map { _ -> HTTPClient.Task<TestHTTPDelegate.Response> in
+            var task: HTTPClient.Task<Void>!
+            let delegate = HeadReceivedCallback { _ in
+                // request is definitely running because we just received a head from the server
+                cancelPool.next().execute {
+                    // canceling from a different thread
+                    task.cancel()
+                }
+            }
+            task = client.execute(
+                request: request,
+                delegate: delegate
+            )
+            return task
+        }
+
+        for task in tasks {
+            XCTAssertThrowsError(try task.futureResult.timeout(after: .seconds(2)).wait()) {
+                XCTAssertEqual($0 as? HTTPClientError, .cancelled)
+            }
+        }
+    }
+
+    func testPlatformConnectErrorIsForwardedOnTimeout() {
+        let bin = HTTPBin(.http2(compress: false))
+        let clientGroup = MultiThreadedEventLoopGroup(numberOfThreads: 2)
+        let el1 = clientGroup.next()
+        let el2 = clientGroup.next()
+        defer { XCTAssertNoThrow(try clientGroup.syncShutdownGracefully()) }
+        var tlsConfig = TLSConfiguration.makeClientConfiguration()
+        tlsConfig.certificateVerification = .none
+        let client = HTTPClient(
+            eventLoopGroupProvider: .shared(clientGroup),
+            configuration: HTTPClient.Configuration(
+                tlsConfiguration: tlsConfig,
+                timeout: .init(connect: .milliseconds(1000)),
+                httpVersion: .automatic
+            ),
+            backgroundActivityLogger: Logger(label: "HTTPClient", factory: StreamLogHandler.standardOutput(label:))
+        )
+        defer { XCTAssertNoThrow(try client.syncShutdown()) }
+
+        var maybeRequest1: HTTPClient.Request?
+        XCTAssertNoThrow(maybeRequest1 = try HTTPClient.Request(url: "https://localhost:\(bin.port)/get"))
+        guard let request1 = maybeRequest1 else { return }
+
+        let task1 = client.execute(request: request1, delegate: ResponseAccumulator(request: request1), eventLoop: .delegateAndChannel(on: el1))
+        var response1: ResponseAccumulator.Response?
+        XCTAssertNoThrow(response1 = try task1.wait())
+
+        XCTAssertEqual(.ok, response1?.status)
+        XCTAssertEqual(response1?.version, .http2)
+        let serverPort = bin.port
+        XCTAssertNoThrow(try bin.shutdown())
+        // client is now in HTTP/2 state and the HTTPBin is closed
+        // start a new server on the old port which closes all connections immediately
+        let serverGroup = MultiThreadedEventLoopGroup(numberOfThreads: 1)
+        defer { XCTAssertNoThrow(try serverGroup.syncShutdownGracefully()) }
+        var maybeServer: Channel?
+        XCTAssertNoThrow(maybeServer = try ServerBootstrap(group: serverGroup)
+            .serverChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+            .childChannelInitializer { channel in
+                channel.close()
+            }
+            .childChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+            .bind(host: "0.0.0.0", port: serverPort)
+            .wait())
+        guard let server = maybeServer else { return }
+        defer { XCTAssertNoThrow(try server.close().wait()) }
+
+        var maybeRequest2: HTTPClient.Request?
+        XCTAssertNoThrow(maybeRequest2 = try HTTPClient.Request(url: "https://localhost:\(serverPort)/"))
+        guard let request2 = maybeRequest2 else { return }
+
+        let task2 = client.execute(request: request2, delegate: ResponseAccumulator(request: request2), eventLoop: .delegateAndChannel(on: el2))
+        XCTAssertThrowsError(try task2.wait()) { error in
+            XCTAssertNil(
+                error as? HTTPClientError,
+                "error should be some platform specific error that the connection is closed/reset by the other side"
+            )
+        }
+    }
+}
+
+private final class HeadReceivedCallback: HTTPClientResponseDelegate {
+    typealias Response = Void
+    private let didReceiveHeadCallback: (HTTPResponseHead) -> Void
+    init(didReceiveHead: @escaping (HTTPResponseHead) -> Void) {
+        self.didReceiveHeadCallback = didReceiveHead
+    }
+
+    func didReceiveHead(task: HTTPClient.Task<Void>, _ head: HTTPResponseHead) -> EventLoopFuture<Void> {
+        self.didReceiveHeadCallback(head)
+        return task.eventLoop.makeSucceededVoidFuture()
+    }
+
+    func didFinishRequest(task: HTTPClient.Task<Void>) throws {}
+}
+
+/// sends some headers and waits indefinitely afterwards
+private final class SendHeaderAndWaitChannelHandler: ChannelInboundHandler {
+    typealias InboundIn = HTTPServerRequestPart
+    typealias OutboundOut = HTTPServerResponsePart
+
+    func channelRead(context: ChannelHandlerContext, data: NIOAny) {
+        let requestPart = self.unwrapInboundIn(data)
+        switch requestPart {
+        case .head:
+            context.writeAndFlush(self.wrapOutboundOut(.head(HTTPResponseHead(
+                version: HTTPVersion(major: 1, minor: 1),
+                status: .ok
+            ))
+            ), promise: nil)
+        case .body, .end:
+            return
+        }
+    }
 }