diff --git a/Turbolinks/Session.swift b/Turbolinks/Session.swift
index ce95a36..98cfd33 100644
--- a/Turbolinks/Session.swift
+++ b/Turbolinks/Session.swift
@@ -10,6 +10,10 @@ public protocol SessionDelegate: class {
     func sessionDidFinishRequest(_ session: Session)
 }
 
+public protocol SessionDataSource: class {
+    func session(_ session: Session, additionalHeadersForRequestWithURL url: URL) -> [String: String]?
+}
+
 public extension SessionDelegate {
     func sessionDidLoadWebView(_ session: Session) {
         session.webView.navigationDelegate = session
@@ -26,8 +30,15 @@ public extension SessionDelegate {
     }
 }
 
+public extension SessionDataSource {
+    func session(_ session: Session, additionalHeadersForRequestWithURL url: URL) -> [String: String]? {
+        return nil
+    }
+}
+
 open class Session: NSObject {
     open weak var delegate: SessionDelegate?
+    open weak var dataSource: SessionDataSource?
 
     open var webView: WKWebView {
         return _webView
@@ -78,6 +89,7 @@ open class Session: NSObject {
         currentVisit = visit
 
         visit.delegate = self
+        visit.dataSource = self
         visit.start()
     }
 
@@ -195,6 +207,12 @@ extension Session: VisitDelegate {
     }
 }
 
+extension Session: VisitDataSource {
+    func visit(_ visit: Visit, additionalHeadersForRequestWithURL url: URL) -> [String : String]? {
+        return dataSource?.session(self, additionalHeadersForRequestWithURL: url)
+    }
+}
+
 extension Session: VisitableDelegate {
     public func visitableViewWillAppear(_ visitable: Visitable) {
         guard let topmostVisit = self.topmostVisit, let currentVisit = self.currentVisit else { return }
diff --git a/Turbolinks/Visit.swift b/Turbolinks/Visit.swift
index 24f39fb..8c07dfc 100644
--- a/Turbolinks/Visit.swift
+++ b/Turbolinks/Visit.swift
@@ -17,6 +17,10 @@ protocol VisitDelegate: class {
     func visitRequestDidFinish(_ visit: Visit)
 }
 
+protocol VisitDataSource: class {
+    func visit(_ visit: Visit, additionalHeadersForRequestWithURL url: URL) -> [String: String]?
+}
+
 enum VisitState {
     case initialized
     case started
@@ -27,6 +31,7 @@ enum VisitState {
 
 class Visit: NSObject {
     weak var delegate: VisitDelegate?
+    weak var dataSource: VisitDataSource?
 
     var visitable: Visitable
     var action: Action
@@ -141,7 +146,12 @@ class ColdBootVisit: Visit, WKNavigationDelegate, WebViewPageLoadDelegate {
         webView.navigationDelegate = self
         webView.pageLoadDelegate = self
 
-        let request = URLRequest(url: location)
+        var request = URLRequest(url: location)
+        if let headers = dataSource?.visit(self, additionalHeadersForRequestWithURL: location) {
+            for header in headers {
+                request.setValue(header.value, forHTTPHeaderField: header.key)
+            }
+        }
         navigation = webView.load(request)
 
         delegate?.visitDidStart(self)