diff --git a/src/swift/Dispatch.apinotes b/src/swift/Dispatch.apinotes
index 6e804515a..d40bb68a4 100644
--- a/src/swift/Dispatch.apinotes
+++ b/src/swift/Dispatch.apinotes
@@ -91,6 +91,8 @@ Protocols:
   SwiftName: DispatchSourceUserDataOr
 - Name: OS_dispatch_source_data_add
   SwiftName: DispatchSourceUserDataAdd
+- Name: OS_dispatch_source_data_replace
+  SwiftName: DispatchSourceUserDataReplace
 - Name: OS_dispatch_source_vnode
   SwiftName: DispatchSourceFileSystemObject
 - Name: OS_dispatch_source_write
diff --git a/src/swift/DispatchStubs.cc b/src/swift/DispatchStubs.cc
index c81768ab8..2c76b7b47 100644
--- a/src/swift/DispatchStubs.cc
+++ b/src/swift/DispatchStubs.cc
@@ -26,6 +26,7 @@
 @protocol OS_dispatch_source_timer;
 @protocol OS_dispatch_source_data_add;
 @protocol OS_dispatch_source_data_or;
+@protocol OS_dispatch_source_data_replace;
 @protocol OS_dispatch_source_vnode;
 @protocol OS_dispatch_source_write;
 
@@ -44,6 +45,7 @@ static void _dispatch_overlay_constructor() {
     class_addProtocol(source, @protocol(OS_dispatch_source_timer));
     class_addProtocol(source, @protocol(OS_dispatch_source_data_add));
     class_addProtocol(source, @protocol(OS_dispatch_source_data_or));
+    class_addProtocol(source, @protocol(OS_dispatch_source_data_replace));
     class_addProtocol(source, @protocol(OS_dispatch_source_vnode));
     class_addProtocol(source, @protocol(OS_dispatch_source_write));
   }
@@ -186,6 +188,7 @@ _swift_dispatch_retain(dispatch_object_t obj) {
 
 SOURCE(DATA_ADD)
 SOURCE(DATA_OR)
+SOURCE(DATA_REPLACE)
 #if HAVE_MACH
 SOURCE(MACH_SEND)
 SOURCE(MACH_RECV)
diff --git a/src/swift/Source.swift b/src/swift/Source.swift
index 801ae71e3..a3a7e7903 100644
--- a/src/swift/Source.swift
+++ b/src/swift/Source.swift
@@ -201,6 +201,11 @@ public extension DispatchSource {
 		let source = dispatch_source_create(_swift_dispatch_source_type_data_or(), 0, 0, queue?.__wrapped)
 		return DispatchSource(source: source) as DispatchSourceUserDataOr
 	}
+    
+	public class func makeUserDataReplaceSource(queue: DispatchQueue? = nil) -> DispatchSourceUserDataReplace {
+		let source = dispatch_source_create(_swift_dispatch_source_type_data_replace(), 0, 0, queue?.__wrapped)
+		return DispatchSource(source: source) as DispatchSourceUserDataReplace
+	}
 
 #if !os(Linux) && !os(Android)
 	public class func makeFileSystemObjectSource(fileDescriptor: Int32, eventMask: FileSystemEvent, queue: DispatchQueue? = nil) -> DispatchSourceFileSystemObject {
@@ -318,45 +323,48 @@ public extension DispatchSourceFileSystemObject {
 #endif
 
 public extension DispatchSourceUserDataAdd {
-	/// @function mergeData
-	///
-	/// @abstract
-	/// Merges data into a dispatch source of type DISPATCH_SOURCE_TYPE_DATA_ADD or
-	/// DISPATCH_SOURCE_TYPE_DATA_OR and submits its event handler block to its
-	/// target queue.
+	/// Merges data into a dispatch source of type `DISPATCH_SOURCE_TYPE_DATA_ADD`
+	/// and submits its event handler block to its target queue.
 	///
-	/// @param value
-	/// The value to coalesce with the pending data using a logical OR or an ADD
-	/// as specified by the dispatch source type. A value of zero has no effect
-	/// and will not result in the submission of the event handler block.
+	/// - parameter data: the value to add to the current pending data. A value of zero
+	///		has no effect and will not result in the submission of the event handler block.
 	public func add(data: UInt) {
 		dispatch_source_merge_data((self as! DispatchSource).__wrapped, data)
 	}
 }
 
 public extension DispatchSourceUserDataOr {
-	/// @function mergeData
-	///
-	/// @abstract
-	/// Merges data into a dispatch source of type DISPATCH_SOURCE_TYPE_DATA_ADD or
-	/// DISPATCH_SOURCE_TYPE_DATA_OR and submits its event handler block to its
-	/// target queue.
+	/// Merges data into a dispatch source of type `DISPATCH_SOURCE_TYPE_DATA_OR` and
+	/// submits its event handler block to its target queue.
 	///
-	/// @param value
-	/// The value to coalesce with the pending data using a logical OR or an ADD
-	/// as specified by the dispatch source type. A value of zero has no effect
-	/// and will not result in the submission of the event handler block.
+	/// - parameter data: The value to OR into the current pending data. A value of zero
+	///		has no effect and will not result in the submission of the event handler block.
 	public func or(data: UInt) {
 		dispatch_source_merge_data((self as! DispatchSource).__wrapped, data)
 	}
 }
 
+public extension DispatchSourceUserDataReplace {
+	/// Merges data into a dispatch source of type `DISPATCH_SOURCE_TYPE_DATA_REPLACE`
+	/// and submits its event handler block to its target queue.
+	///
+	/// - parameter data: The value that will replace the current pending data.
+	///		A value of zero will be stored but will not result in the submission of the event
+	///		handler block.
+	public func replace(data: UInt) {
+		dispatch_source_merge_data((self as! DispatchSource).__wrapped, data)
+	}
+}
+
 @_silgen_name("_swift_dispatch_source_type_DATA_ADD")
 internal func _swift_dispatch_source_type_data_add() -> dispatch_source_type_t
 
 @_silgen_name("_swift_dispatch_source_type_DATA_OR")
 internal func _swift_dispatch_source_type_data_or() -> dispatch_source_type_t
 
+@_silgen_name("_swift_dispatch_source_type_DATA_REPLACE")
+internal func _swift_dispatch_source_type_data_replace() -> dispatch_source_type_t
+
 #if HAVE_MACH
 @_silgen_name("_swift_dispatch_source_type_MACH_SEND")
 internal func _swift_dispatch_source_type_mach_send() -> dispatch_source_type_t
diff --git a/src/swift/Wrapper.swift b/src/swift/Wrapper.swift
index ece006d6b..5a551dfba 100644
--- a/src/swift/Wrapper.swift
+++ b/src/swift/Wrapper.swift
@@ -158,7 +158,7 @@ public class DispatchSource : DispatchObject,
 	DispatchSourceProtocol,	DispatchSourceRead,
 	DispatchSourceSignal, DispatchSourceTimer,
 	DispatchSourceUserDataAdd, DispatchSourceUserDataOr,
-	DispatchSourceWrite {
+	DispatchSourceUserDataReplace, DispatchSourceWrite {
 	internal let __wrapped:dispatch_source_t
 
 	final internal override func wrapped() -> dispatch_object_t {
@@ -243,6 +243,10 @@ public protocol DispatchSourceUserDataOr : DispatchSourceProtocol {
 	func or(data: UInt)
 }
 
+public protocol DispatchSourceUserDataReplace : DispatchSourceProtocol {
+	func replace(data: UInt)
+}
+
 #if HAVE_MACH
 public protocol DispatchSourceMachSend : DispatchSourceProtocol {
 	public var handle: mach_port_t { get }