diff --git a/.swift-version b/.swift-version
new file mode 100644
index 0000000..5186d07
--- /dev/null
+++ b/.swift-version
@@ -0,0 +1 @@
+4.0
diff --git a/README.md b/README.md
index 89757c7..48dbb5a 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,7 @@ class ViewController: FormViewController {
 ## Requirements
 
 * iOS 8.0+
-* Xcode 8.3+
+* Xcode 9.0+
 
 ## Getting involved