diff --git a/.swift-version b/.swift-version
new file mode 100644
index 0000000..a1ef0ca
--- /dev/null
+++ b/.swift-version
@@ -0,0 +1 @@
+5.0.2
diff --git a/Package@swift-4.swift b/Package@swift-4.swift
new file mode 100644
index 0000000..d95cdd3
--- /dev/null
+++ b/Package@swift-4.swift
@@ -0,0 +1,32 @@
+// swift-tools-version:4.0
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+
+import PackageDescription
+
+let package = Package(
+    name: "Kitura-CredentialsJWT",
+    products: [
+        // Products define the executables and libraries produced by a package, and make them visible to other packages.
+        .library(
+            name: "CredentialsJWT",
+            targets: ["CredentialsJWT"]
+        )
+    ],
+    dependencies: [
+        .package(url: "https://github.com/IBM-Swift/Kitura-Credentials.git", from: "2.4.0"),
+        .package(url: "https://github.com/IBM-Swift/Swift-JWT.git", from: "3.1.0"),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+        .target(
+            name: "CredentialsJWT",
+            dependencies: ["Credentials", "SwiftJWT"]
+        ),
+//        .testTarget(
+//            name: "CredentialsJWTTests",
+//            dependencies: ["CredentialsJWT"]
+//        )
+    ]
+)
diff --git a/Sources/CredentialsJWT/AnyHashableMetatype.swift b/Sources/CredentialsJWT/AnyHashableMetatype.swift
index 8680689..95b2776 100644
--- a/Sources/CredentialsJWT/AnyHashableMetatype.swift
+++ b/Sources/CredentialsJWT/AnyHashableMetatype.swift
@@ -25,7 +25,13 @@ struct AnyHashableMetatype: Hashable {
         self.base = base
     }
 
+    #if swift(>=4.2)
     func hash(into hasher: inout Hasher) {
         hasher.combine(ObjectIdentifier(base))
     }
+    #else
+    var hashValue: Int {
+        return ObjectIdentifier(base).hashValue
+    }
+    #endif
 }
diff --git a/Sources/CredentialsJWT/TypeSafeJWT.swift b/Sources/CredentialsJWT/TypeSafeJWT.swift
index 47478d0..ef3d341 100644
--- a/Sources/CredentialsJWT/TypeSafeJWT.swift
+++ b/Sources/CredentialsJWT/TypeSafeJWT.swift
@@ -89,7 +89,7 @@ extension JWT: TypeSafeCredentials {
     }
     
     private static var usersCache: NSCache<NSString, JWTCacheElement<T>> {
-        let key = String(reflecting: Self.self)
+        let key = String(reflecting: JWT.self)
         if let usersCache = TypeSafeJWTCache<T>.cacheForType[key] {
             return usersCache
         } else {
@@ -134,13 +134,13 @@ extension JWT: TypeSafeCredentials {
         onSuccess(jwt)
 }
     
-    static func getFromCache(token: String) -> Self? {
+    static func getFromCache(token: String) -> JWT? {
         #if os(Linux)
         let key = NSString(string: token)
         #else
         let key = token as NSString
         #endif
-        guard let cacheElement = Self.usersCache.object(forKey: key) else {
+        guard let cacheElement = JWT.usersCache.object(forKey: key) else {
             Log.debug("Cached token not found: \(token)")
             return nil
         }
@@ -155,13 +155,13 @@ extension JWT: TypeSafeCredentials {
         return cacheElement.userProfile
     }
 
-    static func saveInCache(profile: Self, token: String) {
+    static func saveInCache(profile: JWT, token: String) {
         #if os(Linux)
         let key = NSString(string: token)
         #else
         let key = token as NSString
         #endif
-        Self.usersCache.setObject(JWTCacheElement(profile: profile), forKey: key)
+        JWT.usersCache.setObject(JWTCacheElement(profile: profile), forKey: key)
         Log.debug("Token added to cache: \(token)")
     }
 }