diff --git a/Package.swift b/Package.swift
index e276ba2..e0c28d9 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,26 +1,22 @@
-// swift-tools-version:5.0
-// The swift-tools-version declares the minimum version of Swift required to build this package.
+// swift-tools-version:5.5
+
 import PackageDescription
 
 let package = Package(
     name: "StoryFlow",
     platforms: [
         .iOS(.v10),
-    ], products: [
-        // Products define the executables and libraries produced by a package, and make them visible to other packages.
+    ],
+    products: [
         .library(
             name: "StoryFlow",
-            targets: ["StoryFlow"]),
-    ],
-    dependencies: [
-        // Dependencies declare other packages that this package depends on.
-        // .package(url: /* package url */, from: "1.0.0"),
+            targets: ["StoryFlow"]
+        ),
     ],
     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: "StoryFlow",
-            dependencies: []),
+            dependencies: []
+        ),
     ]
 )
diff --git a/Sources/StoryFlow/Interfaces/Helpers/OneOf.swift b/Sources/StoryFlow/Interfaces/Helpers/OneOf.swift
index ab74acd..a72366b 100644
--- a/Sources/StoryFlow/Interfaces/Helpers/OneOf.swift
+++ b/Sources/StoryFlow/Interfaces/Helpers/OneOf.swift
@@ -29,6 +29,33 @@ public indirect enum OneOf8<T1, T2, T3, T4, T5, T6, T7, T8> {
     case t1(T1), t2(T2), t3(T3), t4(T4), t5(T5), t6(T6), t7(T7), t8(T8)
 }
 
+// MARK: - Sendable
+
+extension OneOf2: Sendable
+where T1: Sendable, T2: Sendable {}
+
+extension OneOf3: Sendable
+where T1: Sendable, T2: Sendable, T3: Sendable {}
+
+extension OneOf4: Sendable
+where T1: Sendable, T2: Sendable, T3: Sendable, T4: Sendable {}
+
+extension OneOf5: Sendable
+where T1: Sendable, T2: Sendable, T3: Sendable, T4: Sendable,
+      T5: Sendable {}
+
+extension OneOf6: Sendable
+where T1: Sendable, T2: Sendable, T3: Sendable, T4: Sendable,
+      T5: Sendable, T6: Sendable {}
+
+extension OneOf7: Sendable
+where T1: Sendable, T2: Sendable, T3: Sendable, T4: Sendable,
+      T5: Sendable, T6: Sendable, T7: Sendable {}
+
+extension OneOf8: Sendable
+where T1: Sendable, T2: Sendable, T3: Sendable, T4: Sendable,
+      T5: Sendable, T6: Sendable, T7: Sendable, T8: Sendable {}
+
 // MARK: - Equatable
 
 extension OneOf2: Equatable