diff --git a/Defaults.podspec b/Defaults.podspec
index c2a0249..c8b1140 100644
--- a/Defaults.podspec
+++ b/Defaults.podspec
@@ -8,7 +8,7 @@ Pod::Spec.new do |s|
 	s.authors = { 'Sindre Sorhus' => 'sindresorhus@gmail.com' }
 	s.source = { :git => 'https://github.com/sindresorhus/Defaults.git', :tag => "v#{s.version}" }
 	s.source_files = 'Sources/*.swift'
-	s.swift_version = '5'
+	s.swift_version = '5.0'
 	s.macos.deployment_target = '10.12'
 	s.ios.deployment_target = '10.0'
 	s.tvos.deployment_target = '10.0'
diff --git a/Defaults.xcodeproj/project.pbxproj b/Defaults.xcodeproj/project.pbxproj
index 3797718..0e05184 100644
--- a/Defaults.xcodeproj/project.pbxproj
+++ b/Defaults.xcodeproj/project.pbxproj
@@ -364,19 +364,19 @@
 				TargetAttributes = {
 					52D6D97B1BEFF229002C0205 = {
 						CreatedOnToolsVersion = 7.1;
-						LastSwiftMigration = 1000;
+						LastSwiftMigration = 1020;
 					};
 					52D6D9851BEFF229002C0205 = {
 						CreatedOnToolsVersion = 7.1;
-						LastSwiftMigration = 1000;
+						LastSwiftMigration = 1020;
 					};
 					52D6D9E11BEFFF6E002C0205 = {
 						CreatedOnToolsVersion = 7.1;
-						LastSwiftMigration = 1000;
+						LastSwiftMigration = 1020;
 					};
 					52D6D9EF1BEFFFBE002C0205 = {
 						CreatedOnToolsVersion = 7.1;
-						LastSwiftMigration = 1000;
+						LastSwiftMigration = 1020;
 					};
 					52D6DA0E1BF000BD002C0205 = {
 						CreatedOnToolsVersion = 7.1;
@@ -388,7 +388,7 @@
 					};
 					DD75028C1C690C7A006590AF = {
 						CreatedOnToolsVersion = 7.2.1;
-						LastSwiftMigration = 1000;
+						LastSwiftMigration = 1020;
 					};
 				};
 			};
@@ -694,7 +694,7 @@
 				SKIP_INSTALL = YES;
 				SWIFT_COMPILATION_MODE = singlefile;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -721,7 +721,7 @@
 				SKIP_INSTALL = YES;
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};
@@ -742,7 +742,7 @@
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_COMPILATION_MODE = singlefile;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -763,7 +763,7 @@
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};
@@ -787,7 +787,7 @@
 				PRODUCT_NAME = Defaults;
 				SDKROOT = watchos;
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 4;
 				WATCHOS_DEPLOYMENT_TARGET = 3.0;
 			};
@@ -815,7 +815,7 @@
 				SKIP_INSTALL = YES;
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 4;
 				WATCHOS_DEPLOYMENT_TARGET = 3.0;
 			};
@@ -841,7 +841,7 @@
 				PRODUCT_NAME = Defaults;
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 3;
 				TVOS_DEPLOYMENT_TARGET = 10.0;
 			};
@@ -869,7 +869,7 @@
 				SKIP_INSTALL = YES;
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = 3;
 				TVOS_DEPLOYMENT_TARGET = 10.0;
 			};
@@ -984,7 +984,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				PROVISIONING_PROFILE_SPECIFIER = "";
 				SDKROOT = appletvos;
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TVOS_DEPLOYMENT_TARGET = 10.0;
 			};
 			name = Debug;
@@ -1006,7 +1006,7 @@
 				SDKROOT = appletvos;
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
-				SWIFT_VERSION = 4.2;
+				SWIFT_VERSION = 5.0;
 				TVOS_DEPLOYMENT_TARGET = 10.0;
 			};
 			name = Release;