diff --git a/src/Avalonia.Base/PropertyStore/ConstantValueEntry.cs b/src/Avalonia.Base/PropertyStore/ConstantValueEntry.cs
index dc4a1d88c1..ebcd064626 100644
--- a/src/Avalonia.Base/PropertyStore/ConstantValueEntry.cs
+++ b/src/Avalonia.Base/PropertyStore/ConstantValueEntry.cs
@@ -30,7 +30,7 @@ namespace Avalonia.PropertyStore
             IValueSink sink)
         {
             Property = property;
-            _value = value;
+            _value = value!;
             Priority = priority;
             _sink = sink;
         }