diff --git a/.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata b/.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
new file mode 100644
index 0000000..919434a
--- /dev/null
+++ b/.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "self:">
+   </FileRef>
+</Workspace>
diff --git a/Package.swift b/Package.swift
index 51efd73..91fce65 100644
--- a/Package.swift
+++ b/Package.swift
@@ -15,5 +15,5 @@ let package = Package(
         sources: ["Sources"]
       )
     ],
-    swiftLanguageVersions: [3, 4, 5]
+    swiftLanguageVersions: [.v4, .v4_2, .v5]
 )