diff --git a/Sources/AsyncHTTPClient/AsyncAwait/HTTPClientRequest+Prepared.swift b/Sources/AsyncHTTPClient/AsyncAwait/HTTPClientRequest+Prepared.swift
new file mode 100644
index 000000000..8eacb4f47
--- /dev/null
+++ b/Sources/AsyncHTTPClient/AsyncAwait/HTTPClientRequest+Prepared.swift
@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the AsyncHTTPClient open source project
+//
+// Copyright (c) 2021 Apple Inc. and the AsyncHTTPClient project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of AsyncHTTPClient project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#if compiler(>=5.5) && canImport(_Concurrency)
+import NIOHTTP1
+
+@available(macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0, *)
+extension HTTPClientRequest {
+    struct Prepared {
+        var poolKey: ConnectionPool.Key
+        var requestFramingMetadata: RequestFramingMetadata
+        var head: HTTPRequestHead
+        var body: Body?
+    }
+}
+
+@available(macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0, *)
+extension HTTPClientRequest.Prepared {
+    init(_ request: HTTPClientRequest) throws {
+        let url = try DeconstructedURL(url: request.url)
+
+        var headers = request.headers
+        headers.addHostIfNeeded(for: url)
+        let metadata = try headers.validateAndSetTransportFraming(
+            method: request.method,
+            bodyLength: .init(request.body)
+        )
+
+        self.init(
+            poolKey: .init(url: url, tlsConfiguration: nil),
+            requestFramingMetadata: metadata,
+            head: .init(
+                version: .http1_1,
+                method: request.method,
+                uri: url.uri,
+                headers: headers
+            ),
+            body: request.body
+        )
+    }
+}
+
+@available(macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0, *)
+extension RequestBodyLength {
+    init(_ body: HTTPClientRequest.Body?) {
+        switch body?.mode {
+        case .none:
+            self = .fixed(length: 0)
+        case .byteBuffer(let buffer):
+            self = .fixed(length: buffer.readableBytes)
+        case .sequence(nil, _), .asyncSequence(nil, _):
+            self = .dynamic
+        case .sequence(.some(let length), _), .asyncSequence(.some(let length), _):
+            self = .fixed(length: length)
+        }
+    }
+}
+
+#endif
diff --git a/Sources/AsyncHTTPClient/ConnectionPool.swift b/Sources/AsyncHTTPClient/ConnectionPool.swift
index cd884fd26..0dac50e5f 100644
--- a/Sources/AsyncHTTPClient/ConnectionPool.swift
+++ b/Sources/AsyncHTTPClient/ConnectionPool.swift
@@ -12,6 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+import NIOSSL
+
 enum ConnectionPool {
     /// Used by the `ConnectionPool` to index its `HTTP1ConnectionProvider`s
     ///
@@ -23,12 +25,14 @@ enum ConnectionPool {
         var connectionTarget: ConnectionTarget
         private var tlsConfiguration: BestEffortHashableTLSConfiguration?
 
-        init(_ request: HTTPClient.Request) {
-            self.scheme = request.deconstructedURL.scheme
-            self.connectionTarget = request.deconstructedURL.connectionTarget
-            if let tls = request.tlsConfiguration {
-                self.tlsConfiguration = BestEffortHashableTLSConfiguration(wrapping: tls)
-            }
+        init(
+            scheme: Scheme,
+            connectionTarget: ConnectionTarget,
+            tlsConfiguration: BestEffortHashableTLSConfiguration? = nil
+        ) {
+            self.scheme = scheme
+            self.connectionTarget = connectionTarget
+            self.tlsConfiguration = tlsConfiguration
         }
 
         var description: String {
@@ -48,3 +52,22 @@ enum ConnectionPool {
         }
     }
 }
+
+extension ConnectionPool.Key {
+    init(url: DeconstructedURL, tlsConfiguration: TLSConfiguration?) {
+        self.init(
+            scheme: url.scheme,
+            connectionTarget: url.connectionTarget,
+            tlsConfiguration: tlsConfiguration.map {
+                BestEffortHashableTLSConfiguration(wrapping: $0)
+            }
+        )
+    }
+
+    init(_ request: HTTPClient.Request) {
+        self.init(
+            url: request.deconstructedURL,
+            tlsConfiguration: request.tlsConfiguration
+        )
+    }
+}
diff --git a/Sources/AsyncHTTPClient/ConnectionTarget.swift b/Sources/AsyncHTTPClient/ConnectionTarget.swift
index 3b4dfd465..207a6e1bb 100644
--- a/Sources/AsyncHTTPClient/ConnectionTarget.swift
+++ b/Sources/AsyncHTTPClient/ConnectionTarget.swift
@@ -40,3 +40,25 @@ enum ConnectionTarget: Equatable, Hashable {
         }
     }
 }
+
+extension ConnectionTarget {
+    /// The host name which will be send as an HTTP `Host` header.
+    /// Only returns nil if the `self` is a `unixSocket`.
+    var host: String? {
+        switch self {
+        case .ipAddress(let serialization, _): return serialization
+        case .domain(let name, _): return name
+        case .unixSocket: return nil
+        }
+    }
+
+    /// The host name which will be send as an HTTP host header.
+    /// Only returns nil if the `self` is a `unixSocket`.
+    var port: Int? {
+        switch self {
+        case .ipAddress(_, let address): return address.port!
+        case .domain(_, let port): return port
+        case .unixSocket: return nil
+        }
+    }
+}
diff --git a/Sources/AsyncHTTPClient/DeconstructedURL.swift b/Sources/AsyncHTTPClient/DeconstructedURL.swift
index a4ab658c8..020c17455 100644
--- a/Sources/AsyncHTTPClient/DeconstructedURL.swift
+++ b/Sources/AsyncHTTPClient/DeconstructedURL.swift
@@ -31,6 +31,13 @@ struct DeconstructedURL {
 }
 
 extension DeconstructedURL {
+    init(url: String) throws {
+        guard let url = URL(string: url) else {
+            throw HTTPClientError.invalidURL
+        }
+        try self.init(url: url)
+    }
+
     init(url: URL) throws {
         guard let schemeString = url.scheme else {
             throw HTTPClientError.emptyScheme
diff --git a/Sources/AsyncHTTPClient/HTTPHandler.swift b/Sources/AsyncHTTPClient/HTTPHandler.swift
index 2cf805fcd..e745726cb 100644
--- a/Sources/AsyncHTTPClient/HTTPHandler.swift
+++ b/Sources/AsyncHTTPClient/HTTPHandler.swift
@@ -200,20 +200,12 @@ extension HTTPClient {
 
         /// Remote host, resolved from `URL`.
         public var host: String {
-            switch self.deconstructedURL.connectionTarget {
-            case .ipAddress(let serialization, _): return serialization
-            case .domain(let name, _): return name
-            case .unixSocket: return ""
-            }
+            self.deconstructedURL.connectionTarget.host ?? ""
         }
 
         /// Resolved port.
         public var port: Int {
-            switch self.deconstructedURL.connectionTarget {
-            case .ipAddress(_, let address): return address.port!
-            case .domain(_, let port): return port
-            case .unixSocket: return self.deconstructedURL.scheme.defaultPort
-            }
+            self.deconstructedURL.connectionTarget.port ?? self.deconstructedURL.scheme.defaultPort
         }
 
         /// Whether request will be executed using secure socket.
@@ -227,14 +219,7 @@ extension HTTPClient {
                 headers: self.headers
             )
 
-            if !head.headers.contains(name: "host") {
-                let port = self.port
-                var host = self.host
-                if !(port == 80 && self.deconstructedURL.scheme == .http), !(port == 443 && self.deconstructedURL.scheme == .https) {
-                    host += ":\(port)"
-                }
-                head.headers.add(name: "host", value: host)
-            }
+            head.headers.addHostIfNeeded(for: self.deconstructedURL)
 
             let metadata = try head.headers.validateAndSetTransportFraming(method: self.method, bodyLength: .init(self.body))
 
diff --git a/Sources/AsyncHTTPClient/RequestValidation.swift b/Sources/AsyncHTTPClient/RequestValidation.swift
index 359b1496a..ea0370484 100644
--- a/Sources/AsyncHTTPClient/RequestValidation.swift
+++ b/Sources/AsyncHTTPClient/RequestValidation.swift
@@ -110,3 +110,20 @@ extension HTTPHeaders {
         }
     }
 }
+
+extension HTTPHeaders {
+    mutating func addHostIfNeeded(for url: DeconstructedURL) {
+        // if no host header was set, let's use the url host
+        guard !self.contains(name: "host"),
+              var host = url.connectionTarget.host
+        else {
+            return
+        }
+        // if the request uses a non-default port, we need to add it after the host
+        if let port = url.connectionTarget.port,
+           port != url.scheme.defaultPort {
+            host += ":\(port)"
+        }
+        self.add(name: "host", value: host)
+    }
+}