diff --git a/.swift-version b/.swift-version
index 8c50098..5186d07 100644
--- a/.swift-version
+++ b/.swift-version
@@ -1 +1 @@
-3.1
+4.0
diff --git a/Cache.podspec b/Cache.podspec
index 12228d8..3579da3 100644
--- a/Cache.podspec
+++ b/Cache.podspec
@@ -21,5 +21,5 @@ Pod::Spec.new do |s|
   s.frameworks = 'Foundation'
   s.dependency 'SwiftHash', '~> 1.4.0'
 
-  s.pod_target_xcconfig = { 'SWIFT_VERSION' => '3.0' }
+  s.pod_target_xcconfig = { 'SWIFT_VERSION' => '4.0' }
 end