diff --git a/API.md b/API.md
index 2ef55b2..fc9916e 100644
--- a/API.md
+++ b/API.md
@@ -52,15 +52,211 @@ public enum HTTPBodyChunk {
 }
 
 /// Headers structure.
-public struct HTTPHeaders {
-    var storage: [String:[String]]     /* lower cased keys */
-    var original: [(String, String)]   /* original casing */
-    let description: String
-    
-    public subscript(key: String) -> [String]
-    func makeIterator() -> IndexingIterator<Array<(String, String)>>
-    
-    public init(_ headers: [(String, String)] = [])
+public struct HTTPHeaders : Sequence, ExpressibleByDictionaryLiteral {
+    public subscript(name: Name) -> String?
+    public subscript(valuesFor name: Name) -> [String]
+
+    public struct Literal : ExpressibleByDictionaryLiteral { }
+    public mutating func append(_ literal: HTTPHeaders.Literal)
+    public mutating func replace(_ literal: HTTPHeaders.Literal)
+
+    public func makeIterator() -> AnyIterator<(name: Name, value: String)>
+
+    public struct Name : Hashable, ExpressibleByStringLiteral, CustomStringConvertible {
+        public init(_ name: String)
+
+        // https://www.iana.org/assignments/message-headers/message-headers.xhtml
+        // Permanent Message Header Field Names
+        public static let aIM
+        public static let accept
+        public static let acceptAdditions
+        public static let acceptCharset
+        public static let acceptDatetime
+        public static let acceptEncoding
+        public static let acceptFeatures
+        public static let acceptLanguage
+        public static let acceptPatch
+        public static let acceptPost
+        public static let acceptRanges
+        public static let age
+        public static let allow
+        public static let alpn
+        public static let altSvc
+        public static let altUsed
+        public static let alternates
+        public static let applyToRedirectRef
+        public static let authenticationControl
+        public static let authenticationInfo
+        public static let authorization
+        public static let cExt
+        public static let cMan
+        public static let cOpt
+        public static let cPEP
+        public static let cPEPInfo
+        public static let cacheControl
+        public static let calDAVTimezones
+        public static let close
+        public static let connection
+        public static let contentBase
+        public static let contentDisposition
+        public static let contentEncoding
+        public static let contentID
+        public static let contentLanguage
+        public static let contentLength
+        public static let contentLocation
+        public static let contentMD5
+        public static let contentRange
+        public static let contentScriptType
+        public static let contentStyleType
+        public static let contentType
+        public static let contentVersion
+        public static let cookie
+        public static let cookie2
+        public static let dasl
+        public static let dav
+        public static let date
+        public static let defaultStyle
+        public static let deltaBase
+        public static let depth
+        public static let derivedFrom
+        public static let destination
+        public static let differentialID
+        public static let digest
+        public static let eTag
+        public static let expect
+        public static let expires
+        public static let ext
+        public static let forwarded
+        public static let from
+        public static let getProfile
+        public static let hobareg
+        public static let host
+        public static let http2Settings
+        public static let im
+        public static let `if`
+        public static let ifMatch
+        public static let ifModifiedSince
+        public static let ifNoneMatch
+        public static let ifRange
+        public static let ifScheduleTagMatch
+        public static let ifUnmodifiedSince
+        public static let keepAlive
+        public static let label
+        public static let lastModified
+        public static let link
+        public static let location
+        public static let lockToken
+        public static let man
+        public static let maxForwards
+        public static let mementoDatetime
+        public static let meter
+        public static let mimeVersion
+        public static let negotiate
+        public static let opt
+        public static let optionalWWWAuthenticate
+        public static let orderingType
+        public static let origin
+        public static let overwrite
+        public static let p3p
+        public static let pep
+        public static let picsLabel
+        public static let pepInfo
+        public static let position
+        public static let pragma
+        public static let prefer
+        public static let preferenceApplied
+        public static let profileObject
+        public static let `protocol`
+        public static let protocolInfo
+        public static let protocolQuery
+        public static let protocolRequest
+        public static let proxyAuthenticate
+        public static let proxyAuthenticationInfo
+        public static let proxyAuthorization
+        public static let proxyFeatures
+        public static let proxyInstruction
+        public static let `public`
+        public static let publicKeyPins
+        public static let publicKeyPinsReportOnly
+        public static let range
+        public static let redirectRef
+        public static let referer
+        public static let retryAfter
+        public static let safe
+        public static let scheduleReply
+        public static let scheduleTag
+        public static let secWebSocketAccept
+        public static let secWebSocketExtensions
+        public static let secWebSocketKey
+        public static let secWebSocketProtocol
+        public static let secWebSocketVersion
+        public static let securityScheme
+        public static let server
+        public static let setCookie
+        public static let setCookie2
+        public static let setProfile
+        public static let slug
+        public static let soapAction
+        public static let statusURI
+        public static let strictTransportSecurity
+        public static let surrogateCapability
+        public static let surrogateControl
+        public static let tcn
+        public static let te
+        public static let timeout
+        public static let topic
+        public static let trailer
+        public static let transferEncoding
+        public static let ttl
+        public static let urgency
+        public static let uri
+        public static let upgrade
+        public static let userAgent
+        public static let variantVary
+        public static let vary
+        public static let via
+        public static let wwwAuthenticate
+        public static let wantDigest
+        public static let warning
+        public static let xFrameOptions
+
+        // https://www.iana.org/assignments/message-headers/message-headers.xhtml
+        // Provisional Message Header Field Names
+        public static let accessControl
+        public static let accessControlAllowCredentials
+        public static let accessControlAllowHeaders
+        public static let accessControlAllowMethods
+        public static let accessControlAllowOrigin
+        public static let accessControlMaxAge
+        public static let accessControlRequestMethod
+        public static let accessControlRequestHeaders
+        public static let compliance
+        public static let contentTransferEncoding
+        public static let cost
+        public static let ediintFeatures
+        public static let messageID
+        public static let methodCheck
+        public static let methodCheckExpires
+        public static let nonCompliance
+        public static let optional
+        public static let refererRoot
+        public static let resolutionHint
+        public static let resolverLocation
+        public static let subOK
+        public static let subst
+        public static let title
+        public static let uaColor
+        public static let uaMedia
+        public static let uaPixels
+        public static let uaResolution
+        public static let uaWindowpixels
+        public static let version
+        public static let xDeviceAccept
+        public static let xDeviceAcceptCharset
+        public static let xDeviceAcceptEncoding
+        public static let xDeviceAcceptLanguage
+        public static let xDeviceUserAgent
+    }
 }
 
 /// Version number of the HTTP Protocol
diff --git a/Sources/HTTP/HTTPCommon.swift b/Sources/HTTP/HTTPCommon.swift
index 1ec333b..447c390 100644
--- a/Sources/HTTP/HTTPCommon.swift
+++ b/Sources/HTTP/HTTPCommon.swift
@@ -17,55 +17,6 @@ public protocol WebAppContaining: class {
     func serve(req: HTTPRequest, res: HTTPResponseWriter ) -> HTTPBodyProcessing
 }
 
-/// Headers structure.
-public struct HTTPHeaders {
-    var storage: [String: [String]]     /* lower cased keys */
-    var original: [(String, String)]   /* original casing */
-    let description: String
-    
-    public subscript(key: String) -> [String] {
-        get {
-            return storage[key.lowercased()] ?? []
-        }
-        mutating set {
-            original = original.filter { $0.0 != key.lowercased() }
-            storage[key.lowercased()]=nil
-            for val in newValue {
-                self.append(newHeader: (key, val))
-            }
-        }
-    }
-    
-    func makeIterator() -> IndexingIterator<Array<(String, String)>> {
-        return original.makeIterator()
-    }
-    
-    public mutating func append(newHeader: (String, String)) {
-        original.append(newHeader)
-        let key = newHeader.0.lowercased()
-        let val = newHeader.1
-        
-        var existing = storage[key] ?? []
-        existing.append(val)
-        storage[key] = existing
-    }
-
-    /// Create Header structure from an array of string pairs
-    public init(_ headers: [(String, String)] = []) {
-        original = headers
-        description = ""
-        storage = [String: [String]]()
-        makeIterator().forEach { (element: (String, String)) in
-            let key = element.0.lowercased()
-            let val = element.1
-            
-            var existing = storage[key] ?? []
-            existing.append(val)
-            storage[key] = existing
-        }
-    }
-}
-
 public enum Result<POSIXError, Void> {
     case success(())
     case failure(POSIXError)
diff --git a/Sources/HTTP/HTTPHeaders.swift b/Sources/HTTP/HTTPHeaders.swift
new file mode 100644
index 0000000..8cfc366
--- /dev/null
+++ b/Sources/HTTP/HTTPHeaders.swift
@@ -0,0 +1,336 @@
+/// Headers structure.
+public struct HTTPHeaders {
+    var original: [(name: Name, value: String)]?
+    var storage: [Name: [String]] {
+        didSet { original = nil }
+    }
+
+    public subscript(name: Name) -> String? {
+        get {
+            guard let value = storage[name] else { return nil }
+            switch name {
+                case Name.setCookie: // Exception, see note in [RFC7230, section 3.2.2]
+                    return value.isEmpty ? nil : value[0]
+                default:
+                    return value.joined(separator: ",")
+            }
+        }
+        set {
+            storage[name] = newValue.map { [$0] }
+        }
+    }
+
+    public subscript(valuesFor name: Name) -> [String] {
+        get { return storage[name] ?? [] }
+        set { storage[name] = newValue.isEmpty ? nil : newValue }
+    }
+}
+
+extension HTTPHeaders : ExpressibleByDictionaryLiteral {
+    public init(dictionaryLiteral: (Name, String)...) {
+        storage = [:]
+        for (name, value) in dictionaryLiteral {
+#if swift(>=4.0)
+            storage[name, default: []].append(value)
+#else
+            if storage[name] == nil {
+                storage[name] = [value]
+            } else {
+                storage[name]!.append(value)
+            }
+#endif
+        }
+        original = dictionaryLiteral
+    }
+}
+
+extension HTTPHeaders {
+    // Used instead of HTTPHeaders to save CPU on dictionary construction
+    public struct Literal : ExpressibleByDictionaryLiteral {
+        let fields: [(name: Name, value: String)]
+
+        public init(dictionaryLiteral: (Name, String)...) {
+            fields = dictionaryLiteral
+        }
+    }
+
+    public mutating func append(_ literal: HTTPHeaders.Literal) {
+        for (name, value) in literal.fields {
+#if swift(>=4.0)
+            storage[name, default: []].append(value)
+#else
+            if storage[name] == nil {
+                storage[name] = [value]
+            } else {
+                storage[name]!.append(value)
+            }
+#endif
+        }
+    }
+
+    public mutating func replace(_ literal: HTTPHeaders.Literal) {
+        for (name, _) in literal.fields {
+            storage[name] = []
+        }
+        for (name, value) in literal.fields {
+            storage[name]!.append(value)
+        }
+    }
+}
+
+extension HTTPHeaders : Sequence {
+    public func makeIterator() -> AnyIterator<(name: Name, value: String)> {
+        if let original = original {
+            return AnyIterator(original.makeIterator())
+        } else {
+            return AnyIterator(StorageIterator(storage.makeIterator()))
+        }
+    }
+
+    struct StorageIterator : IteratorProtocol {
+        var headers: DictionaryIterator<Name, [String]>
+        var header: (name: Name, values: IndexingIterator<[String]>)?
+
+        init(_ iterator: DictionaryIterator<Name, [String]>) {
+            headers = iterator
+            header = headers.next().map { (name: $0.key, values: $0.value.makeIterator()) }
+        }
+
+        mutating func next() -> (name: Name, value: String)? {
+            while header != nil {
+                if let value = header!.values.next() {
+                    return (name: header!.name, value: value)
+                } else {
+                    header = headers.next().map { (name: $0.key, values: $0.value.makeIterator()) }
+                }
+            }
+            return nil
+        }
+    }
+}
+
+extension HTTPHeaders {
+    public struct Name : Hashable, ExpressibleByStringLiteral, CustomStringConvertible {
+        let original: String
+        let lowercased: String
+        public let hashValue: Int
+
+        public init(_ name: String) {
+            original = name
+            lowercased = name.lowercased()
+            hashValue = lowercased.hashValue
+        }
+
+        public init(stringLiteral: String) {
+            self.init(stringLiteral)
+        }
+
+        public init(unicodeScalarLiteral: String) {
+            self.init(unicodeScalarLiteral)
+        }
+
+        public init(extendedGraphemeClusterLiteral: String) {
+            self.init(extendedGraphemeClusterLiteral)
+        }
+
+        public var description: String {
+            return original
+        }
+
+        public static func == (lhs: Name, rhs: Name) -> Bool {
+            return lhs.lowercased == rhs.lowercased
+        }
+
+        // https://www.iana.org/assignments/message-headers/message-headers.xhtml
+        // Permanent Message Header Field Names
+        public static let aIM = Name("A-IM")
+        public static let accept = Name("Accept")
+        public static let acceptAdditions = Name("Accept-Additions")
+        public static let acceptCharset = Name("Accept-Charset")
+        public static let acceptDatetime = Name("Accept-Datetime")
+        public static let acceptEncoding = Name("Accept-Encoding")
+        public static let acceptFeatures = Name("Accept-Features")
+        public static let acceptLanguage = Name("Accept-Language")
+        public static let acceptPatch = Name("Accept-Patch")
+        public static let acceptPost = Name("Accept-Post")
+        public static let acceptRanges = Name("Accept-Ranges")
+        public static let age = Name("Age")
+        public static let allow = Name("Allow")
+        public static let alpn = Name("ALPN")
+        public static let altSvc = Name("Alt-Svc")
+        public static let altUsed = Name("Alt-Used")
+        public static let alternates = Name("Alternates")
+        public static let applyToRedirectRef = Name("Apply-To-Redirect-Ref")
+        public static let authenticationControl = Name("Authentication-Control")
+        public static let authenticationInfo = Name("Authentication-Info")
+        public static let authorization = Name("Authorization")
+        public static let cExt = Name("C-Ext")
+        public static let cMan = Name("C-Man")
+        public static let cOpt = Name("C-Opt")
+        public static let cPEP = Name("C-PEP")
+        public static let cPEPInfo = Name("C-PEP-Info")
+        public static let cacheControl = Name("Cache-Control")
+        public static let calDAVTimezones = Name("CalDAV-Timezones")
+        public static let close = Name("Close")
+        public static let connection = Name("Connection")
+        public static let contentBase = Name("Content-Base")
+        public static let contentDisposition = Name("Content-Disposition")
+        public static let contentEncoding = Name("Content-Encoding")
+        public static let contentID = Name("Content-ID")
+        public static let contentLanguage = Name("Content-Language")
+        public static let contentLength = Name("Content-Length")
+        public static let contentLocation = Name("Content-Location")
+        public static let contentMD5 = Name("Content-MD5")
+        public static let contentRange = Name("Content-Range")
+        public static let contentScriptType = Name("Content-Script-Type")
+        public static let contentStyleType = Name("Content-Style-Type")
+        public static let contentType = Name("Content-Type")
+        public static let contentVersion = Name("Content-Version")
+        public static let cookie = Name("Cookie")
+        public static let cookie2 = Name("Cookie2")
+        public static let dasl = Name("DASL")
+        public static let dav = Name("DAV")
+        public static let date = Name("Date")
+        public static let defaultStyle = Name("Default-Style")
+        public static let deltaBase = Name("Delta-Base")
+        public static let depth = Name("Depth")
+        public static let derivedFrom = Name("Derived-From")
+        public static let destination = Name("Destination")
+        public static let differentialID = Name("Differential-ID")
+        public static let digest = Name("Digest")
+        public static let eTag = Name("ETag")
+        public static let expect = Name("Expect")
+        public static let expires = Name("Expires")
+        public static let ext = Name("Ext")
+        public static let forwarded = Name("Forwarded")
+        public static let from = Name("From")
+        public static let getProfile = Name("GetProfile")
+        public static let hobareg = Name("Hobareg")
+        public static let host = Name("Host")
+        public static let http2Settings = Name("HTTP2-Settings")
+        public static let im = Name("IM")
+        public static let `if` = Name("If")
+        public static let ifMatch = Name("If-Match")
+        public static let ifModifiedSince = Name("If-Modified-Since")
+        public static let ifNoneMatch = Name("If-None-Match")
+        public static let ifRange = Name("If-Range")
+        public static let ifScheduleTagMatch = Name("If-Schedule-Tag-Match")
+        public static let ifUnmodifiedSince = Name("If-Unmodified-Since")
+        public static let keepAlive = Name("Keep-Alive")
+        public static let label = Name("Label")
+        public static let lastModified = Name("Last-Modified")
+        public static let link = Name("Link")
+        public static let location = Name("Location")
+        public static let lockToken = Name("Lock-Token")
+        public static let man = Name("Man")
+        public static let maxForwards = Name("Max-Forwards")
+        public static let mementoDatetime = Name("Memento-Datetime")
+        public static let meter = Name("Meter")
+        public static let mimeVersion = Name("MIME-Version")
+        public static let negotiate = Name("Negotiate")
+        public static let opt = Name("Opt")
+        public static let optionalWWWAuthenticate = Name("Optional-WWW-Authenticate")
+        public static let orderingType = Name("Ordering-Type")
+        public static let origin = Name("Origin")
+        public static let overwrite = Name("Overwrite")
+        public static let p3p = Name("P3P")
+        public static let pep = Name("PEP")
+        public static let picsLabel = Name("PICS-Label")
+        public static let pepInfo = Name("Pep-Info")
+        public static let position = Name("Position")
+        public static let pragma = Name("Pragma")
+        public static let prefer = Name("Prefer")
+        public static let preferenceApplied = Name("Preference-Applied")
+        public static let profileObject = Name("ProfileObject")
+        public static let `protocol` = Name("Protocol")
+        public static let protocolInfo = Name("Protocol-Info")
+        public static let protocolQuery = Name("Protocol-Query")
+        public static let protocolRequest = Name("Protocol-Request")
+        public static let proxyAuthenticate = Name("Proxy-Authenticate")
+        public static let proxyAuthenticationInfo = Name("Proxy-Authentication-Info")
+        public static let proxyAuthorization = Name("Proxy-Authorization")
+        public static let proxyFeatures = Name("Proxy-Features")
+        public static let proxyInstruction = Name("Proxy-Instruction")
+        public static let `public` = Name("Public")
+        public static let publicKeyPins = Name("Public-Key-Pins")
+        public static let publicKeyPinsReportOnly = Name("Public-Key-Pins-Report-Only")
+        public static let range = Name("Range")
+        public static let redirectRef = Name("Redirect-Ref")
+        public static let referer = Name("Referer")
+        public static let retryAfter = Name("Retry-After")
+        public static let safe = Name("Safe")
+        public static let scheduleReply = Name("Schedule-Reply")
+        public static let scheduleTag = Name("Schedule-Tag")
+        public static let secWebSocketAccept = Name("Sec-WebSocket-Accept")
+        public static let secWebSocketExtensions = Name("Sec-WebSocket-Extensions")
+        public static let secWebSocketKey = Name("Sec-WebSocket-Key")
+        public static let secWebSocketProtocol = Name("Sec-WebSocket-Protocol")
+        public static let secWebSocketVersion = Name("Sec-WebSocket-Version")
+        public static let securityScheme = Name("Security-Scheme")
+        public static let server = Name("Server")
+        public static let setCookie = Name("Set-Cookie")
+        public static let setCookie2 = Name("Set-Cookie2")
+        public static let setProfile = Name("SetProfile")
+        public static let slug = Name("SLUG")
+        public static let soapAction = Name("SoapAction")
+        public static let statusURI = Name("Status-URI")
+        public static let strictTransportSecurity = Name("Strict-Transport-Security")
+        public static let surrogateCapability = Name("Surrogate-Capability")
+        public static let surrogateControl = Name("Surrogate-Control")
+        public static let tcn = Name("TCN")
+        public static let te = Name("TE")
+        public static let timeout = Name("Timeout")
+        public static let topic = Name("Topic")
+        public static let trailer = Name("Trailer")
+        public static let transferEncoding = Name("Transfer-Encoding")
+        public static let ttl = Name("TTL")
+        public static let urgency = Name("Urgency")
+        public static let uri = Name("URI")
+        public static let upgrade = Name("Upgrade")
+        public static let userAgent = Name("User-Agent")
+        public static let variantVary = Name("Variant-Vary")
+        public static let vary = Name("Vary")
+        public static let via = Name("Via")
+        public static let wwwAuthenticate = Name("WWW-Authenticate")
+        public static let wantDigest = Name("Want-Digest")
+        public static let warning = Name("Warning")
+        public static let xFrameOptions = Name("X-Frame-Options")
+
+        // https://www.iana.org/assignments/message-headers/message-headers.xhtml
+        // Provisional Message Header Field Names
+        public static let accessControl = Name("Access-Control")
+        public static let accessControlAllowCredentials = Name("Access-Control-Allow-Credentials")
+        public static let accessControlAllowHeaders = Name("Access-Control-Allow-Headers")
+        public static let accessControlAllowMethods = Name("Access-Control-Allow-Methods")
+        public static let accessControlAllowOrigin = Name("Access-Control-Allow-Origin")
+        public static let accessControlMaxAge = Name("Access-Control-Max-Age")
+        public static let accessControlRequestMethod = Name("Access-Control-Request-Method")
+        public static let accessControlRequestHeaders = Name("Access-Control-Request-Headers")
+        public static let compliance = Name("Compliance")
+        public static let contentTransferEncoding = Name("Content-Transfer-Encoding")
+        public static let cost = Name("Cost")
+        public static let ediintFeatures = Name("EDIINT-Features")
+        public static let messageID = Name("Message-ID")
+        public static let methodCheck = Name("Method-Check")
+        public static let methodCheckExpires = Name("Method-Check-Expires")
+        public static let nonCompliance = Name("Non-Compliance")
+        public static let optional = Name("Optional")
+        public static let refererRoot = Name("Referer-Root")
+        public static let resolutionHint = Name("Resolution-Hint")
+        public static let resolverLocation = Name("Resolver-Location")
+        public static let subOK = Name("SubOK")
+        public static let subst = Name("Subst")
+        public static let title = Name("Title")
+        public static let uaColor = Name("UA-Color")
+        public static let uaMedia = Name("UA-Media")
+        public static let uaPixels = Name("UA-Pixels")
+        public static let uaResolution = Name("UA-Resolution")
+        public static let uaWindowpixels = Name("UA-Windowpixels")
+        public static let version = Name("Version")
+        public static let xDeviceAccept = Name("X-Device-Accept")
+        public static let xDeviceAcceptCharset = Name("X-Device-Accept-Charset")
+        public static let xDeviceAcceptEncoding = Name("X-Device-Accept-Encoding")
+        public static let xDeviceAcceptLanguage = Name("X-Device-Accept-Language")
+        public static let xDeviceUserAgent = Name("X-Device-User-Agent")
+    }
+}
diff --git a/Sources/HTTP/HTTPStreamingParser.swift b/Sources/HTTP/HTTPStreamingParser.swift
index 9096f2b..40c11f6 100644
--- a/Sources/HTTP/HTTPStreamingParser.swift
+++ b/Sources/HTTP/HTTPStreamingParser.swift
@@ -179,7 +179,7 @@ public class StreamingParser: HTTPResponseWriter {
             }
         case .headerValueReceived:
             if let parserBuffer = self.parserBuffer, let lastHeaderName = self.lastHeaderName, let headerValue = String(data:parserBuffer, encoding: .utf8) {
-                self.parsedHeaders.append(newHeader: (lastHeaderName, headerValue))
+                self.parsedHeaders.append([HTTPHeaders.Name(lastHeaderName): headerValue])
                 self.lastHeaderName = nil
                 self.parserBuffer=nil
             } else {
diff --git a/Tests/BlueSocketHTTPTests/Helpers/EchoWebApp.swift b/Tests/BlueSocketHTTPTests/Helpers/EchoWebApp.swift
index cb253e1..f997833 100644
--- a/Tests/BlueSocketHTTPTests/Helpers/EchoWebApp.swift
+++ b/Tests/BlueSocketHTTPTests/Helpers/EchoWebApp.swift
@@ -17,7 +17,7 @@ class EchoWebApp: WebAppContaining {
         res.writeResponse(HTTPResponse(httpVersion: req.httpVersion,
                                        status: .ok,
                                        transferEncoding: .chunked,
-                                       headers: HTTPHeaders([("X-foo", "bar")])))
+                                       headers: ["X-foo": "bar"]))
         return .processBody { (chunk, stop) in
             switch chunk {
             case .chunk(let data, let finishedProcessing):
diff --git a/Tests/BlueSocketHTTPTests/Helpers/HelloWorldKeepAliveWebApp.swift b/Tests/BlueSocketHTTPTests/Helpers/HelloWorldKeepAliveWebApp.swift
index f8cacb6..ce84333 100644
--- a/Tests/BlueSocketHTTPTests/Helpers/HelloWorldKeepAliveWebApp.swift
+++ b/Tests/BlueSocketHTTPTests/Helpers/HelloWorldKeepAliveWebApp.swift
@@ -16,7 +16,7 @@ class HelloWorldKeepAliveWebApp: WebAppContaining {
         res.writeResponse(HTTPResponse(httpVersion: req.httpVersion,
                                        status: .ok,
                                        transferEncoding: .chunked,
-                                       headers: HTTPHeaders([("Connection","Keep-Alive"),("Keep-Alive","timeout=5, max=10")])))
+                                       headers: ["Connection": "Keep-Alive", "Keep-Alive": "timeout=5, max=10"]))
         return .processBody { (chunk, stop) in
             switch chunk {
             case .chunk(_, let finishedProcessing):
diff --git a/Tests/BlueSocketHTTPTests/Helpers/HelloWorldWebApp.swift b/Tests/BlueSocketHTTPTests/Helpers/HelloWorldWebApp.swift
index 9353389..5294b95 100644
--- a/Tests/BlueSocketHTTPTests/Helpers/HelloWorldWebApp.swift
+++ b/Tests/BlueSocketHTTPTests/Helpers/HelloWorldWebApp.swift
@@ -16,7 +16,7 @@ class HelloWorldWebApp: WebAppContaining {
         res.writeResponse(HTTPResponse(httpVersion: req.httpVersion,
                                        status: .ok,
                                        transferEncoding: .chunked,
-                                       headers: HTTPHeaders([("X-foo", "bar")])))
+                                       headers: ["X-foo": "bar"]))
         return .processBody { (chunk, stop) in
             switch chunk {
             case .chunk(_, let finishedProcessing):
diff --git a/Tests/BlueSocketHTTPTests/ServerTests.swift b/Tests/BlueSocketHTTPTests/ServerTests.swift
index 0a026ef..569aac0 100644
--- a/Tests/BlueSocketHTTPTests/ServerTests.swift
+++ b/Tests/BlueSocketHTTPTests/ServerTests.swift
@@ -13,7 +13,7 @@ import XCTest
 
 class ServerTests: XCTestCase {
     func testResponseOK() {
-        let request = HTTPRequest(method: .GET, target:"/echo", httpVersion: HTTPVersion(major: 1, minor: 1), headers: HTTPHeaders([("X-foo", "bar")]))
+        let request = HTTPRequest(method: .GET, target:"/echo", httpVersion: HTTPVersion(major: 1, minor: 1), headers: ["X-foo": "bar"])
         let resolver = TestResponseResolver(request: request, requestBody: Data())
         resolver.resolveHandler(EchoWebApp().serve)
         XCTAssertNotNil(resolver.response)
@@ -23,7 +23,7 @@ class ServerTests: XCTestCase {
 
     func testEcho() {
         let testString="This is a test"
-        let request = HTTPRequest(method: .POST, target:"/echo", httpVersion: HTTPVersion(major: 1, minor: 1), headers: HTTPHeaders([("X-foo", "bar")]))
+        let request = HTTPRequest(method: .POST, target:"/echo", httpVersion: HTTPVersion(major: 1, minor: 1), headers: ["X-foo": "bar"])
         let resolver = TestResponseResolver(request: request, requestBody: testString.data(using: .utf8)!)
         resolver.resolveHandler(EchoWebApp().serve)
         XCTAssertNotNil(resolver.response)
@@ -33,7 +33,7 @@ class ServerTests: XCTestCase {
     }
     
     func testHello() {
-        let request = HTTPRequest(method: .GET, target:"/helloworld", httpVersion: HTTPVersion(major: 1, minor: 1), headers: HTTPHeaders([("X-foo", "bar")]))
+        let request = HTTPRequest(method: .GET, target:"/helloworld", httpVersion: HTTPVersion(major: 1, minor: 1), headers: ["X-foo": "bar"])
         let resolver = TestResponseResolver(request: request, requestBody: Data())
         resolver.resolveHandler(HelloWorldWebApp().serve)
         XCTAssertNotNil(resolver.response)
@@ -43,13 +43,13 @@ class ServerTests: XCTestCase {
     }
     
     func testSimpleHello() {
-        let request = HTTPRequest(method: .GET, target:"/helloworld", httpVersion: HTTPVersion(major: 1, minor: 1), headers: HTTPHeaders([("X-foo", "bar")]))
+        let request = HTTPRequest(method: .GET, target:"/helloworld", httpVersion: HTTPVersion(major: 1, minor: 1), headers: ["X-foo": "bar"])
         let resolver = TestResponseResolver(request: request, requestBody: Data())
         let simpleHelloWebApp = SimpleResponseCreator { (request, body) -> (reponse: HTTPResponse, responseBody: Data) in
             return (HTTPResponse(httpVersion: request.httpVersion,
                                  status: .ok,
                                  transferEncoding: .chunked,
-                                 headers: HTTPHeaders([("X-foo", "bar")])),
+                                 headers: ["X-foo": "bar"]),
                     "Hello, World!".data(using: .utf8)!)
             
         }
@@ -96,7 +96,7 @@ class ServerTests: XCTestCase {
             return (HTTPResponse(httpVersion: request.httpVersion,
                                  status: .ok,
                                  transferEncoding: .chunked,
-                                 headers: HTTPHeaders([("X-foo", "bar")])),
+                                 headers: ["X-foo": "bar"]),
                     "Hello, World!".data(using: .utf8)!)
             
         }
diff --git a/Tests/HTTPTests/HeadersTests.swift b/Tests/HTTPTests/HeadersTests.swift
index 785463a..072f819 100644
--- a/Tests/HTTPTests/HeadersTests.swift
+++ b/Tests/HTTPTests/HeadersTests.swift
@@ -12,21 +12,51 @@ import XCTest
 
 class HeadersTests: XCTestCase {
     func testHeaders() {
-        var headers = HTTPHeaders()
+        var headers: HTTPHeaders = [
+            .accept: "text/html",
+            "Accept": "application/xhtml+xml",
+            "Accept": "application/xml;q=0.9",
+            "accept": "image/webp",
+            .accept: "*/*;q=0.8",
+            "Accept-Language": "ru-RU,ru;q=0.8",
+            .acceptLanguage: "en-US;q=0.6",
+            "accept-language": "en;q=0.4",
+            "Content-Length": "200",
+            "Set-Cookie": "test1=0; expires=Tue, 21 Jun 2016 16:26:50 GMT; path=/; domain=.my.mail.ru",
+            "Set-Cookie": "test2=0; expires=Tue, 21 Jun 2016 16:26:50 GMT; path=/; domain=.my.mail.ru",
+        ]
+
+        XCTAssertEqual(headers["Content-Length"], "200")
+        XCTAssertEqual(headers["content-length"], "200")
+        XCTAssertEqual(headers[.contentLength], "200")
+        XCTAssertEqual(headers[.accept], "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8")
+        XCTAssertEqual(headers[.acceptLanguage], "ru-RU,ru;q=0.8,en-US;q=0.6,en;q=0.4")
+        XCTAssertEqual(headers[.setCookie], "test1=0; expires=Tue, 21 Jun 2016 16:26:50 GMT; path=/; domain=.my.mail.ru")
+
+        XCTAssertEqual(headers[valuesFor: "Content-Length"], ["200"])
+        XCTAssertEqual(headers[valuesFor: "content-length"], ["200"])
+        XCTAssertEqual(headers[valuesFor: .contentLength], ["200"])
+        XCTAssertEqual(headers[valuesFor: .accept], ["text/html", "application/xhtml+xml", "application/xml;q=0.9", "image/webp", "*/*;q=0.8"])
+        XCTAssertEqual(headers[valuesFor: .setCookie], [
+            "test1=0; expires=Tue, 21 Jun 2016 16:26:50 GMT; path=/; domain=.my.mail.ru",
+            "test2=0; expires=Tue, 21 Jun 2016 16:26:50 GMT; path=/; domain=.my.mail.ru",
+        ])
+
+        headers = HTTPHeaders()
         let initialCount = headers.makeIterator().reduce(0) { (last, element) -> Int in return last + 1 }
         XCTAssertEqual(0, initialCount)
 
-        headers.append(newHeader: ("Test-Header","Test Value"))
+        headers.append(["Test-Header": "Test Value"])
         let nextCount = headers.makeIterator().reduce(0) { (last, element) -> Int in return last + 1 }
         XCTAssertEqual(1, nextCount)
 
-        let testHeaderValueArray = headers["test-header"]
+        let testHeaderValueArray = headers[valuesFor: "test-header"]
         XCTAssertNotNil(testHeaderValueArray)
         XCTAssertEqual(1,testHeaderValueArray.count)
         XCTAssertEqual("Test Value",testHeaderValueArray.first ?? "Not Found")
 
-        headers.append(newHeader: ("Test-header","Test Value 2"))
-        let testHeaderValueArray2 = headers["test-header"]
+        headers.append(["Test-header": "Test Value 2"])
+        let testHeaderValueArray2 = headers[valuesFor: "test-header"]
         XCTAssertNotNil(testHeaderValueArray2)
         XCTAssertEqual(2,testHeaderValueArray2.count)
         XCTAssertEqual("Test Value",testHeaderValueArray2.first ?? "Not Found")
@@ -34,14 +64,14 @@ class HeadersTests: XCTestCase {
         XCTAssertEqual("Test Value 2",testHeaderValueArray2Remainder.first ?? "Not Found")
 
         //This should overwrites, since the subscript is documented to use lowercase keys
-        headers["TEST-HEADER"]=["Test Value 3"]
-        let testHeaderValueArray3 = headers["test-header"]
+        headers[valuesFor: "TEST-HEADER"]=["Test Value 3"]
+        let testHeaderValueArray3 = headers[valuesFor: "test-header"]
         XCTAssertNotNil(testHeaderValueArray3)
         XCTAssertEqual(1,testHeaderValueArray3.count)
 
         //Overwrite
-        headers["TEST-HEADER"]=["Test Value 4a","Test Value 4b"]
-        let testHeaderValueArray4 = headers["test-header"]
+        headers[valuesFor: "TEST-HEADER"]=["Test Value 4a","Test Value 4b"]
+        let testHeaderValueArray4 = headers[valuesFor: "test-header"]
         XCTAssertNotNil(testHeaderValueArray4)
         XCTAssertEqual(2,testHeaderValueArray4.count)
         XCTAssertEqual("Test Value 4a",testHeaderValueArray4.first ?? "Not Found")