diff --git a/MySensors.xcodeproj/project.pbxproj b/MySensors.xcodeproj/project.pbxproj
index 4136a1e..cd63eca 100644
--- a/MySensors.xcodeproj/project.pbxproj
+++ b/MySensors.xcodeproj/project.pbxproj
@@ -93,6 +93,7 @@
 				TargetAttributes = {
 					479D566E1D97A76D00713B6E = {
 						CreatedOnToolsVersion = 8.0;
+						LastSwiftMigration = 1000;
 						ProvisioningStyle = Automatic;
 					};
 				};
@@ -250,7 +251,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = me.aisk.MySensors;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.2;
 			};
 			name = Debug;
 		};
@@ -263,7 +265,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = me.aisk.MySensors;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.2;
 			};
 			name = Release;
 		};
diff --git a/MySensors/AppDelegate.swift b/MySensors/AppDelegate.swift
index 0646670..1309e32 100644
--- a/MySensors/AppDelegate.swift
+++ b/MySensors/AppDelegate.swift
@@ -21,10 +21,10 @@ class AppDelegate: NSObject, NSApplicationDelegate, NSMenuDelegate {
             let alert = NSAlert()
             alert.messageText = "initailize SMC failed!"
             alert.runModal()
-            NSApplication.shared().terminate(self)
+            NSApplication.shared.terminate(self)
         }
         
-        statusItem = NSStatusBar.system().statusItem(withLength: NSSquareStatusItemLength)
+        statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.squareLength)
         let icon = NSImage(named: "ic_memory")
         icon?.isTemplate = true
         statusItem.image = icon
@@ -36,8 +36,8 @@ class AppDelegate: NSObject, NSApplicationDelegate, NSMenuDelegate {
         let _ = SMCKit.close()
     }
     
-    func onQuitMenuItemClicked(_ sender: NSMenuItem) {
-        NSApplication.shared().terminate(self)
+    @objc func onQuitMenuItemClicked(_ sender: NSMenuItem) {
+        NSApplication.shared.terminate(self)
     }
     
     func menuWillOpen(_ menu: NSMenu) {