diff --git a/Foundation/Data.swift b/Foundation/Data.swift
index b9cb5f5983..da948de344 100644
--- a/Foundation/Data.swift
+++ b/Foundation/Data.swift
@@ -435,12 +435,12 @@ public struct Data : ReferenceConvertible, CustomStringConvertible, Equatable, H
     ///
     /// In some cases, (for example, a `Data` backed by a `dispatch_data_t`, the bytes may be stored discontiguously. In those cases, this function invokes the closure for each contiguous region of bytes.
     /// - parameter block: The closure to invoke for each region of data. You may stop the enumeration by setting the `stop` parameter to `true`.
-    public func enumerateBytes(_ block: @noescape (buffer: UnsafeBufferPointer<UInt8>, byteIndex: Index, stop: inout Bool) -> Void) {
+    public func enumerateBytes(_ block: @noescape (_ buffer: UnsafeBufferPointer<UInt8>, _ byteIndex: Index, _ stop: inout Bool) -> Void) {
         _mapUnmanaged {
             $0.enumerateBytes { (ptr, range, stop) in
                 var stopv = false
                 let bytePtr = ptr.bindMemory(to: UInt8.self, capacity: range.length)
-                block(buffer: UnsafeBufferPointer(start: bytePtr, count: range.length), byteIndex: range.length, stop: &stopv)
+                block(UnsafeBufferPointer(start: bytePtr, count: range.length), range.length, &stopv)
                 if stopv {
                     stop.pointee = true
                 }
diff --git a/Foundation/NSData.swift b/Foundation/NSData.swift
index f5cf5fa41f..75d5b07e88 100644
--- a/Foundation/NSData.swift
+++ b/Foundation/NSData.swift
@@ -257,7 +257,7 @@ extension NSData {
     internal struct NSDataReadResult {
         var bytes: UnsafeMutableRawPointer
         var length: Int
-        var deallocator: ((buffer: UnsafeMutableRawPointer, length: Int) -> Void)?
+        var deallocator: ((_ buffer: UnsafeMutableRawPointer, _ length: Int) -> Void)?
     }
     
     internal static func readBytesFromFileWithExtendedAttributes(_ path: String, options: ReadingOptions) throws -> NSDataReadResult {
diff --git a/Foundation/NSError.swift b/Foundation/NSError.swift
index 20e8410c7b..056d95afca 100644
--- a/Foundation/NSError.swift
+++ b/Foundation/NSError.swift
@@ -153,7 +153,7 @@ public class NSError : NSObject, NSCopying, NSSecureCoding, NSCoding {
         return userInfo[NSHelpAnchorErrorKey] as? String
     }
     
-    internal typealias NSErrorProvider = (error: NSError, key: String) -> AnyObject?
+    internal typealias NSErrorProvider = (_ error: NSError, _ key: String) -> AnyObject?
     internal static var userInfoProviders = [String: NSErrorProvider]()
     
     public class func setUserInfoValueProviderForDomain(_ errorDomain: String, provider: ((NSError, String) -> AnyObject?)?) {
diff --git a/Foundation/String.swift b/Foundation/String.swift
index 91e4b783c6..02517ce3fa 100644
--- a/Foundation/String.swift
+++ b/Foundation/String.swift
@@ -404,12 +404,12 @@ extension String {
   //     enumerateLinesUsing:(void (^)(NSString *line, BOOL *stop))block
 
   /// Enumerates all the lines in a string.
-  public func enumerateLines(_ body: (line: String, stop: inout Bool) -> ()) {
+  public func enumerateLines(_ body: (_ line: String, _ stop: inout Bool) -> ()) {
     _ns.enumerateLines {
       (line: String, stop: UnsafeMutablePointer<ObjCBool>)
     in
       var stop_ = false
-      body(line: line, stop: &stop_)
+      body(line, &stop_)
       if stop_ {
         UnsafeMutablePointer<ObjCBool>(stop).pointee = true
       }
@@ -434,16 +434,16 @@ extension String {
     in range: Range<Index>,
     options opts: EnumerationOptions = [],
     _ body: (
-      substring: String?, substringRange: Range<Index>,
-      enclosingRange: Range<Index>, inout Bool
+      _ substring: String?, _ substringRange: Range<Index>,
+      _ enclosingRange: Range<Index>, inout Bool
     ) -> ()
   ) {
     _ns.enumerateSubstrings(in: _toNSRange(range), options: opts) {
       var stop_ = false
 
-      body(substring: $0,
-        substringRange: self._range($1),
-        enclosingRange: self._range($2),
+      body($0,
+        self._range($1),
+        self._range($2),
         &stop_)
 
       if stop_ {
@@ -1554,8 +1554,8 @@ extension String {
     _ range: Range<Index>,
     options opts: EnumerationOptions = [],
     _ body: (
-      substring: String?, substringRange: Range<Index>,
-      enclosingRange: Range<Index>, inout Bool
+      _ substring: String?, _ substringRange: Range<Index>,
+      _ enclosingRange: Range<Index>, inout Bool
     ) -> ()
   ) {
     fatalError("unavailable function can't be called")