diff --git a/Example/DLRadioButtonExample.xcodeproj/project.pbxproj b/Example/DLRadioButtonExample.xcodeproj/project.pbxproj
index 81d429c..e677e6a 100644
--- a/Example/DLRadioButtonExample.xcodeproj/project.pbxproj
+++ b/Example/DLRadioButtonExample.xcodeproj/project.pbxproj
@@ -156,6 +156,7 @@
 				ORGANIZATIONNAME = "Xingruo Liu";
 				TargetAttributes = {
 					D1BE39FE19A7D263004BD3F5 = {
+						LastSwiftMigration = 1010;
 						SystemCapabilities = {
 							com.apple.DataProtection = {
 								enabled = 0;
@@ -343,6 +344,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE = "";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 4.2;
 				WRAPPER_EXTENSION = app;
 			};
 			name = Debug;
@@ -367,6 +369,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.liuxingruo.$(PRODUCT_NAME)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE = "";
+				SWIFT_VERSION = 4.2;
 				WRAPPER_EXTENSION = app;
 			};
 			name = Release;
diff --git a/Example/DLRadioButtonExample/DemoViewController.swift b/Example/DLRadioButtonExample/DemoViewController.swift
index accaf1a..43137ff 100644
--- a/Example/DLRadioButtonExample/DemoViewController.swift
+++ b/Example/DLRadioButtonExample/DemoViewController.swift
@@ -33,7 +33,7 @@ class DemoViewController : UIViewController {
             if (i > 1) {
                 // put icon on the right side
                 radioButton.isIconOnRight = true;
-                radioButton.contentHorizontalAlignment = UIControlContentHorizontalAlignment.right;
+                radioButton.contentHorizontalAlignment = UIControl.ContentHorizontalAlignment.right;
             }
             otherButtons.append(radioButton);
             i += 1;
@@ -53,8 +53,8 @@ class DemoViewController : UIViewController {
         radioButton.setTitleColor(color, for: []);
         radioButton.iconColor = color;
         radioButton.indicatorColor = color;
-        radioButton.contentHorizontalAlignment = UIControlContentHorizontalAlignment.left;
-        radioButton.addTarget(self, action: #selector(DemoViewController.logSelectedButton), for: UIControlEvents.touchUpInside);
+        radioButton.contentHorizontalAlignment = UIControl.ContentHorizontalAlignment.left;
+        radioButton.addTarget(self, action: #selector(DemoViewController.logSelectedButton), for: UIControl.Event.touchUpInside);
         self.view.addSubview(radioButton);
         
         return radioButton;