diff --git a/SwiftShell/Command.swift b/SwiftShell/Command.swift
index 2ccfe16..a6c53bc 100644
--- a/SwiftShell/Command.swift
+++ b/SwiftShell/Command.swift
@@ -65,9 +65,9 @@ extension ShellRunnable {
 		task.environment = shellcontext.env
 		task.currentDirectoryPath = shellcontext.currentdirectory
 
-		task.standardInput = shellcontext.stdin
+		task.standardInput = shellcontext.stdin.filehandle
 		task.standardOutput = shellcontext.stdout.filehandle
-		task.standardError = shellcontext.stderror
+		task.standardError = shellcontext.stderror.filehandle
 
 		return task
 	}
diff --git a/SwiftShell/Context.swift b/SwiftShell/Context.swift
index dfdb1c9..d5a91cd 100644
--- a/SwiftShell/Context.swift
+++ b/SwiftShell/Context.swift
@@ -11,9 +11,9 @@ public protocol ShellContextType {
 	var encoding: NSStringEncoding {get set}
 	var env: [String: String] {get set}
 
-	var stdin: NSFileHandle {get set}
+	var stdin: ReadableStream {get set}
 	var stdout: WriteableStream {get set}
-	var stderror: NSFileHandle {get set}
+	var stderror: WriteableStream {get set}
 
 	/**
 	The current working directory.
@@ -29,9 +29,9 @@ public struct ShellContext: ShellContextType {
 	public var encoding: NSStringEncoding
 	public var env: [String: String]
 
-	public var stdin: NSFileHandle
+	public var stdin: ReadableStream
 	public var stdout: WriteableStream
-	public var stderror: NSFileHandle
+	public var stderror: WriteableStream
 
 	/**
 	The current working directory.
@@ -46,9 +46,9 @@ public struct ShellContext: ShellContextType {
 		encoding = NSUTF8StringEncoding
 		env = [String:String]()
 
-		stdin =    NSFileHandle.fileHandleWithNullDevice()
+		stdin =    ReadableStream(NSFileHandle.fileHandleWithNullDevice(), encoding: encoding)
 		stdout =   WriteableStream(NSFileHandle.fileHandleWithNullDevice(), encoding: encoding)
-		stderror = NSFileHandle.fileHandleWithNullDevice()
+		stderror = WriteableStream(NSFileHandle.fileHandleWithNullDevice(), encoding: encoding)
 
 		currentdirectory = main.currentdirectory
 	}
@@ -77,9 +77,9 @@ public final class MainShellContext: ShellContextType {
 	public var encoding = NSUTF8StringEncoding
 	public lazy var env = NSProcessInfo.processInfo().environment as [String: String]
 
-	public lazy var stdin    = NSFileHandle.fileHandleWithStandardInput() //as ReadableStreamType
+	public lazy var stdin: ReadableStream = { ReadableStream(NSFileHandle.fileHandleWithStandardInput(), encoding: self.encoding) }()
 	public lazy var stdout: WriteableStream = { WriteableStream(NSFileHandle.fileHandleWithStandardOutput(), encoding: self.encoding) }()
-	public lazy var stderror = NSFileHandle.fileHandleWithStandardError() //as WriteableStreamType
+	public lazy var stderror: WriteableStream = { WriteableStream(NSFileHandle.fileHandleWithStandardError(), encoding: self.encoding) }()
 
 	/**
 	The current working directory.
diff --git a/SwiftShellTests/Command_Tests.swift b/SwiftShellTests/Command_Tests.swift
index fd09072..46fb71d 100644
--- a/SwiftShellTests/Command_Tests.swift
+++ b/SwiftShellTests/Command_Tests.swift
@@ -78,7 +78,7 @@ class RunAndPrint_Tests: XCTestCase {
 		test_stdout = outputpipe.fileHandleForReading
 
 		let errorpipe = NSPipe()
-		main.stderror = errorpipe.fileHandleForWriting
+		main.stderror = WriteableStream(errorpipe.fileHandleForWriting)
 		test_stderr = errorpipe.fileHandleForReading
 	}
 
diff --git a/SwiftShellTests/Context_Tests.swift b/SwiftShellTests/Context_Tests.swift
index 2df5eef..b4b78b8 100644
--- a/SwiftShellTests/Context_Tests.swift
+++ b/SwiftShellTests/Context_Tests.swift
@@ -58,9 +58,9 @@ class BlankShellContext_Tests: XCTestCase {
 	func testIsBlank () {
 		let context = ShellContext()
 
-		XCTAssert( context.stdin === NSFileHandle.fileHandleWithNullDevice() )
+		XCTAssert( context.stdin.filehandle === NSFileHandle.fileHandleWithNullDevice() )
 		XCTAssert( context.stdout.filehandle === NSFileHandle.fileHandleWithNullDevice() )
-		XCTAssert( context.stderror === NSFileHandle.fileHandleWithNullDevice() )
+		XCTAssert( context.stderror.filehandle === NSFileHandle.fileHandleWithNullDevice() )
 	}
 
 	func testNonAbsoluteExecutablePathFailsOnEmptyPATHEnvVariable () {