diff --git a/docs/csharp/programming-guide/classes-and-structs/snippets/ExtensionMembers/CustomExtensionMembers.cs b/docs/csharp/programming-guide/classes-and-structs/snippets/ExtensionMembers/CustomExtensionMembers.cs
index 3adc79b6718ce..ffcee5362483a 100644
--- a/docs/csharp/programming-guide/classes-and-structs/snippets/ExtensionMembers/CustomExtensionMembers.cs
+++ b/docs/csharp/programming-guide/classes-and-structs/snippets/ExtensionMembers/CustomExtensionMembers.cs
@@ -125,7 +125,8 @@ public static class AccountExtensions
 {
     extension(ref Account account)
     {
-        // ref keyword can also appear before the this keyword
+        // account is the receiver (analogous to the this parameter in extension methods).
+        // The ref modifier on the extension block means the receiver is passed by reference.
         public void Deposit(float amount)
         {
             account.balance += amount;