diff --git a/Logger.xcodeproj/project.pbxproj b/Logger.xcodeproj/project.pbxproj
index bc89d56..2236301 100644
--- a/Logger.xcodeproj/project.pbxproj
+++ b/Logger.xcodeproj/project.pbxproj
@@ -210,10 +210,11 @@
 				TargetAttributes = {
 					2E58D35921316C3500BEF81A = {
 						CreatedOnToolsVersion = 10.0;
+						LastSwiftMigration = 1020;
 					};
 					2EBF4B392122AA34008E4117 = {
 						CreatedOnToolsVersion = 10.0;
-						LastSwiftMigration = 1000;
+						LastSwiftMigration = 1020;
 					};
 				};
 			};
@@ -299,7 +300,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.wnagrodzki.UnitTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -316,7 +317,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = com.wnagrodzki.UnitTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;
@@ -452,7 +453,7 @@
 				SKIP_INSTALL = YES;
 				SWIFT_OBJC_BRIDGING_HEADER = "Logger/Logger-Bridging-Header.h";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -471,7 +472,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
 				SWIFT_OBJC_BRIDGING_HEADER = "Logger/Logger-Bridging-Header.h";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;
diff --git a/Logger/Logger.swift b/Logger/Logger.swift
index 7953f48..4107095 100644
--- a/Logger/Logger.swift
+++ b/Logger/Logger.swift
@@ -107,7 +107,7 @@ extension Logger {
     public func log(_ message: @autoclosure () -> String, level: LogLevel, file: String = #file, line: Int = #line, function: String = #function) {
         let now = Date()
         let location = description(for: file, line: line, function: function)
-        log(time: now, level: level, location: location, message: message)
+        log(time: now, level: level, location: location, message: message())
     }
         
     /// Returns location in format `"<file name>:<line> <function>"`.
diff --git a/Logger/Loggers/AgregateLogger.swift b/Logger/Loggers/AgregateLogger.swift
index d9bffe4..eaba542 100644
--- a/Logger/Loggers/AgregateLogger.swift
+++ b/Logger/Loggers/AgregateLogger.swift
@@ -38,7 +38,7 @@ public final class AgregateLogger: Logger {
     
     public func log(time: Date, level: LogLevel, location: String, message: @autoclosure () -> String) {
         for logger in self.loggers {
-            logger.log(time: time, level: level, location: location, message: message)
+            logger.log(time: time, level: level, location: location, message: message())
         }
     }
 }
diff --git a/UnitTests/FileWriterTests.swift b/UnitTests/FileWriterTests.swift
index cb3ebc7..222991c 100644
--- a/UnitTests/FileWriterTests.swift
+++ b/UnitTests/FileWriterTests.swift
@@ -39,7 +39,7 @@ class FileWriterTests: XCTestCase {
     func testKeepingFileSizeLimit() throws {
         let factory = FileMockFactory()
         let writer = try FileWriter(fileURL: logURL, fileSizeLimit: 1, fileFactory: factory)
-        let data = Data(bytes: [0])
+        let data = Data([0])
         try writer.write(data)
         
         XCTAssertEqual(factory.mock.writtenData, data)
@@ -48,7 +48,7 @@ class FileWriterTests: XCTestCase {
     func testExceedingFileSizeLimit() throws {
         let factory = FileMockFactory()
         let writer = try FileWriter(fileURL: logURL, fileSizeLimit: 1, fileFactory: factory)
-        let data = Data(bytes: [0, 0])
+        let data = Data([0, 0])
         
         XCTAssertThrowsError(try writer.write(data), "file size limit exceeded") { (error) in
             XCTAssertTrue(error is SizeLimitedFileQuotaReached)