diff --git a/.swift-version b/.swift-version
index 5186d07..7d5c902 100644
--- a/.swift-version
+++ b/.swift-version
@@ -1 +1 @@
-4.0
+4.1
diff --git a/.travis.yml b/.travis.yml
index 6a3d9a9..b980816 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,16 +1,16 @@
-osx_image: xcode9
+osx_image: xcode9.3
 language: objective-c
 sudo: required
 env:
   global:
     - PROJECT="ReusableKit.xcodeproj"
     - SCHEME="ReusableKit-Package"
-    - IOS_SDK="iphonesimulator11.0"
+    - IOS_SDK="iphonesimulator11.3"
     - MACOS_SDK="macosx10.13"
-    - TVOS_SDK="appletvsimulator11.0"
+    - TVOS_SDK="appletvsimulator11.3"
     - FRAMEWORK="ReusableKit"
   matrix:
-    - SDK="$IOS_SDK"      DESTINATION="platform=iOS Simulator,name=iPhone 8,OS=11.0"
+    - SDK="$IOS_SDK"      DESTINATION="platform=iOS Simulator,name=iPhone 8,OS=11.3"
 
 install:
   - eval "$(curl -sL https://gist.githubusercontent.com/kylef/5c0475ff02b7c7671d2a/raw/9f442512a46d7a2af7b850d65a7e9bd31edfb09b/swiftenv-install.sh)"
diff --git a/README.md b/README.md
index 606b216..6fc43e4 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # ReusableKit
 
-![Swift](https://img.shields.io/badge/Swift-3.1-orange.svg)
+![Swift](https://img.shields.io/badge/Swift-4.1-orange.svg)
 [![CocoaPods](http://img.shields.io/cocoapods/v/ReusableKit.svg)](https://cocoapods.org/pods/ReusableKit)
 [![Build Status](https://travis-ci.org/devxoul/ReusableKit.svg)](https://travis-ci.org/devxoul/ReusableKit)
 [![Codecov](https://img.shields.io/codecov/c/github/devxoul/ReusableKit.svg)](https://codecov.io/gh/devxoul/ReusableKit)
diff --git a/Sources/ReusableKit/ReusableKit.swift b/Sources/ReusableKit/ReusableKit.swift
index 3135980..28120ca 100644
--- a/Sources/ReusableKit/ReusableKit.swift
+++ b/Sources/ReusableKit/ReusableKit.swift
@@ -19,7 +19,7 @@ public struct ReusableCell<Cell: CellType> {
   /// - parameter nib: A `UINib` instance. Use this when registering from xib.
   public init(identifier: String? = nil, nib: UINib? = nil) {
     self.identifier = nib?.instantiate(withOwner: nil, options: nil).lazy
-      .flatMap { ($0 as? CellType)?.reuseIdentifier }
+      .compactMap { ($0 as? CellType)?.reuseIdentifier }
       .first ?? identifier ?? UUID().uuidString
     self.nib = nib
   }