diff --git a/Model/Sources/Model/Piece.swift b/Model/Sources/Model/Piece.swift
index bfc7d4f..13fc00f 100644
--- a/Model/Sources/Model/Piece.swift
+++ b/Model/Sources/Model/Piece.swift
@@ -1,4 +1,4 @@
-public struct Piece {
+public struct Piece : Sendable {
     public let owner: Player
     
     // Required for public visibility
diff --git a/Model/Sources/Model/Player.swift b/Model/Sources/Model/Player.swift
index f4d406a..67f6872 100644
--- a/Model/Sources/Model/Player.swift
+++ b/Model/Sources/Model/Player.swift
@@ -1,3 +1,3 @@
-public enum Player: CaseIterable {
+public enum Player: CaseIterable, Sendable {
     case A, B
 }