diff --git a/src/Prism.Core/Commands/AsyncDelegateCommand.cs b/src/Prism.Core/Commands/AsyncDelegateCommand.cs
index 7781457969..e748ad40d8 100644
--- a/src/Prism.Core/Commands/AsyncDelegateCommand.cs
+++ b/src/Prism.Core/Commands/AsyncDelegateCommand.cs
@@ -86,7 +86,7 @@ public bool IsExecuting
     ///<summary>
     /// Executes the command.
     ///</summary>
-    public async Task Execute(CancellationToken? cancellationToken)
+    public async Task Execute(CancellationToken? cancellationToken = null)
     {
         var token = cancellationToken ?? _getCancellationToken();
         try
diff --git a/src/Prism.Core/Commands/AsyncDelegateCommand{T}.cs b/src/Prism.Core/Commands/AsyncDelegateCommand{T}.cs
index 4f367471f8..4ed68524da 100644
--- a/src/Prism.Core/Commands/AsyncDelegateCommand{T}.cs
+++ b/src/Prism.Core/Commands/AsyncDelegateCommand{T}.cs
@@ -88,7 +88,7 @@ public bool IsExecuting
     ///<summary>
     /// Executes the command.
     ///</summary>
-    public async Task Execute(T parameter, CancellationToken? cancellationToken)
+    public async Task Execute(T parameter, CancellationToken? cancellationToken = null)
     {
         var token = cancellationToken ?? _getCancellationToken();