diff --git a/DesktopNotifications.Apple/DesktopNotifications.Apple.csproj b/DesktopNotifications.Apple/DesktopNotifications.Apple.csproj
index a2bf4d0..4cfdb39 100644
--- a/DesktopNotifications.Apple/DesktopNotifications.Apple.csproj
+++ b/DesktopNotifications.Apple/DesktopNotifications.Apple.csproj
@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <TargetFramework>netcoreapp3.1</TargetFramework>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>