diff --git a/docs/csharp/programming-guide/events/how-to-implement-interface-events.md b/docs/csharp/programming-guide/events/how-to-implement-interface-events.md
index 0561e4e77ad91..81c49af87d8fd 100644
--- a/docs/csharp/programming-guide/events/how-to-implement-interface-events.md
+++ b/docs/csharp/programming-guide/events/how-to-implement-interface-events.md
@@ -29,7 +29,7 @@ namespace ImplementInterfaceEvents
     }  
     public class Shape : IDrawingObject  
     {  
-        public event EventHandler ShapeChanged;  
+        public event EventHandler? ShapeChanged;  
         void ChangeShape()  
         {  
             // Do something here before the event…  
diff --git a/samples/snippets/csharp/VS_Snippets_VBCSharp/csProgGuideEvents/CS/Events.cs b/samples/snippets/csharp/VS_Snippets_VBCSharp/csProgGuideEvents/CS/Events.cs
index 20f6f0797ce1d..6a959a4e65448 100644
--- a/samples/snippets/csharp/VS_Snippets_VBCSharp/csProgGuideEvents/CS/Events.cs
+++ b/samples/snippets/csharp/VS_Snippets_VBCSharp/csProgGuideEvents/CS/Events.cs
@@ -686,10 +686,10 @@ public class MyEventArgs : EventArgs
     }
     public class Shape : IDrawingObject
     {
-        public event EventHandler ShapeChanged;
+        public event EventHandler? ShapeChanged;
         void ChangeShape()
         {
-            // Do something here before the event�
+            // Do something here before the event…
 
             OnShapeChanged(new MyEventArgs(/*arguments*/));
 
@@ -697,10 +697,7 @@ void ChangeShape()
         }
         protected virtual void OnShapeChanged(MyEventArgs e)
         {
-            if (ShapeChanged != null)
-            {
-                ShapeChanged(this, e);
-            }
+            ShapeChanged?.Invoke(this, e);
         }
     }
 }