diff --git a/src/Caliburn.Micro.Platform/Platforms/Maui/ActionMessage.cs b/src/Caliburn.Micro.Platform/Platforms/Maui/ActionMessage.cs
index 06292299..c2a16f3a 100644
--- a/src/Caliburn.Micro.Platform/Platforms/Maui/ActionMessage.cs
+++ b/src/Caliburn.Micro.Platform/Platforms/Maui/ActionMessage.cs
@@ -253,7 +253,8 @@ void OnPropertyChanged(object s, PropertyChangedEventArgs e) {
         public object Handler {
             get => handler;
             private set {
-                if (handler.Equals(value)) {
+                if (handler != null &&
+                    handler.Equals(value)) {
                     return;
                 }