diff --git a/SlimLogger/SlimLogger.swift b/SlimLogger/SlimLogger.swift
index 83eca39..290602b 100644
--- a/SlimLogger/SlimLogger.swift
+++ b/SlimLogger/SlimLogger.swift
@@ -59,34 +59,34 @@ open class Slim {
     }
 
     open class func trace<T>( _ message: @autoclosure () -> T, filename: String = #file, line: Int = #line) {
-        slim.logInternal(message, level: LogLevel.trace, filename: filename, line: line)
+        slim.logInternal(message(), level: LogLevel.trace, filename: filename, line: line)
     }
 
     open class func debug<T>( _ message: @autoclosure () -> T, filename: String = #file, line: Int = #line) {
-        slim.logInternal(message, level: LogLevel.debug, filename: filename, line: line)
+        slim.logInternal(message(), level: LogLevel.debug, filename: filename, line: line)
     }
 
     open class func info<T>( _ message: @autoclosure () -> T, filename: String = #file, line: Int = #line) {
-        slim.logInternal(message, level: LogLevel.info, filename: filename, line: line)
+        slim.logInternal(message(), level: LogLevel.info, filename: filename, line: line)
     }
 
     open class func warn<T>( _ message: @autoclosure () -> T, filename: String = #file, line: Int = #line) {
-        slim.logInternal(message, level: LogLevel.warn, filename: filename, line: line)
+        slim.logInternal(message(), level: LogLevel.warn, filename: filename, line: line)
     }
 
     open class func error<T>( _ message: @autoclosure () -> T, filename: String = #file, line: Int = #line) {
-        slim.logInternal(message, level: LogLevel.error, filename: filename, line: line)
+        slim.logInternal(message(), level: LogLevel.error, filename: filename, line: line)
     }
 
     open class func fatal<T>( _ message: @autoclosure () -> T, filename: String = #file, line: Int = #line) {
-        slim.logInternal(message, level: LogLevel.fatal, filename: filename, line: line)
+        slim.logInternal(message(), level: LogLevel.fatal, filename: filename, line: line)
     }
 
     fileprivate func logInternal<T>( _ message: @autoclosure () -> T, level: LogLevel, filename: String, line: Int) {
         let cleanedfile = cleanedFilename(filename)
         if isSourceFileEnabled(cleanedfile) {
             for dest in logDestinations {
-                dest.log(message, level: level, filename: cleanedfile, line: line)
+                dest.log(message(), level: level, filename: cleanedfile, line: line)
             }
         }
     }
diff --git a/SlimLogger/SlimLogglyDestination.swift b/SlimLogger/SlimLogglyDestination.swift
index b22d293..e0bc54e 100644
--- a/SlimLogger/SlimLogglyDestination.swift
+++ b/SlimLogger/SlimLogglyDestination.swift
@@ -13,7 +13,7 @@ class SlimLogglyDestination: LogDestination {
     var userid: String?
     fileprivate let dateFormatter = DateFormatter()
     fileprivate var buffer: [String] = []
-    fileprivate var backgroundTaskIdentifier: UIBackgroundTaskIdentifier = UIBackgroundTaskInvalid
+    fileprivate var backgroundTaskIdentifier: UIBackgroundTaskIdentifier = UIBackgroundTaskIdentifier.invalid
     fileprivate lazy var standardFields: [String: String] = {
         var dict: [String: String] = [:]
         dict["lang"] = Locale.preferredLanguages[0]
@@ -138,7 +138,7 @@ class SlimLogglyDestination: LogDestination {
                 } else {
                     self.traceMessage(msg: "Neither error nor responsedata, something's wrong")
                 }
-                if self.backgroundTaskIdentifier != UIBackgroundTaskInvalid {
+                if self.backgroundTaskIdentifier != UIBackgroundTaskIdentifier.invalid {
                     self.endBackgroundTask()
                 }
             })
@@ -147,9 +147,9 @@ class SlimLogglyDestination: LogDestination {
     }
 
     private func endBackgroundTask() {
-        if self.backgroundTaskIdentifier != UIBackgroundTaskInvalid {
-            UIApplication.shared.endBackgroundTask(self.backgroundTaskIdentifier)
-            self.backgroundTaskIdentifier = UIBackgroundTaskInvalid
+        if self.backgroundTaskIdentifier != UIBackgroundTaskIdentifier.invalid {
+            UIApplication.shared.endBackgroundTask(convertToUIBackgroundTaskIdentifier(self.backgroundTaskIdentifier.rawValue))
+            self.backgroundTaskIdentifier = UIBackgroundTaskIdentifier.invalid
             print("Ending background task")
         }
     }
@@ -160,3 +160,8 @@ class SlimLogglyDestination: LogDestination {
         }
     }
 }
+
+// Helper function inserted by Swift 4.2 migrator.
+fileprivate func convertToUIBackgroundTaskIdentifier(_ input: Int) -> UIBackgroundTaskIdentifier {
+	return UIBackgroundTaskIdentifier(rawValue: input)
+}
diff --git a/SlimLoggerExampleProject/SlimLoggerExampleProject.xcodeproj/project.pbxproj b/SlimLoggerExampleProject/SlimLoggerExampleProject.xcodeproj/project.pbxproj
index 367be41..eeadd6d 100644
--- a/SlimLoggerExampleProject/SlimLoggerExampleProject.xcodeproj/project.pbxproj
+++ b/SlimLoggerExampleProject/SlimLoggerExampleProject.xcodeproj/project.pbxproj
@@ -194,11 +194,11 @@
 				TargetAttributes = {
 					E51237901B2239DB002EABDC = {
 						CreatedOnToolsVersion = 6.3.1;
-						LastSwiftMigration = 0810;
+						LastSwiftMigration = 1020;
 					};
 					E51237A51B2239DB002EABDC = {
 						CreatedOnToolsVersion = 6.3.1;
-						LastSwiftMigration = 0810;
+						LastSwiftMigration = 1020;
 						TestTargetID = E51237901B2239DB002EABDC;
 					};
 				};
@@ -208,6 +208,7 @@
 			developmentRegion = English;
 			hasScannedForEncodings = 0;
 			knownRegions = (
+				English,
 				en,
 				Base,
 			);
@@ -406,7 +407,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "se.baresi.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -419,7 +420,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "se.baresi.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};
@@ -439,7 +440,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "se.baresi.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 5.0;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/SlimLoggerExampleProject.app/SlimLoggerExampleProject";
 			};
 			name = Debug;
@@ -456,7 +457,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "se.baresi.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 5.0;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/SlimLoggerExampleProject.app/SlimLoggerExampleProject";
 			};
 			name = Release;
diff --git a/SlimLoggerExampleProject/SlimLoggerExampleProject/AppDelegate.swift b/SlimLoggerExampleProject/SlimLoggerExampleProject/AppDelegate.swift
index 60f323f..d1d0e67 100644
--- a/SlimLoggerExampleProject/SlimLoggerExampleProject/AppDelegate.swift
+++ b/SlimLoggerExampleProject/SlimLoggerExampleProject/AppDelegate.swift
@@ -14,7 +14,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
     var window: UIWindow?
 
 
-    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
+    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
         // Override point for customization after application launch.
         let logglyDestination = SlimLogglyDestination()
         logglyDestination.userid = "johndoe"