diff --git a/Down.podspec b/Down.podspec
index 5a4f7c90..3e06212c 100644
--- a/Down.podspec
+++ b/Down.podspec
@@ -20,4 +20,5 @@ Pod::Spec.new do |spec|
   spec.compiler_flags = '-Wno-shorten-64-to-32'
   spec.ios.resource = 'Resources/DownView.bundle'
   spec.osx.resource = 'Resources/DownView.bundle'
+  spec.swift_version = "4.0"
 end