diff --git a/vs4win/Chapter05/PacktLibraryModern/Book.cs b/vs4win/Chapter05/PacktLibraryModern/Book.cs
index cfbfa51..78c2ed2 100644
--- a/vs4win/Chapter05/PacktLibraryModern/Book.cs
+++ b/vs4win/Chapter05/PacktLibraryModern/Book.cs
@@ -7,7 +7,7 @@ public class Book
   public Book() { } // For use with initialization syntax.
 
   [SetsRequiredMembers]
-  public Book(string isbn, string title)
+  public Book(string? isbn, string? title)
   {
     Isbn = isbn;
     Title = title;
diff --git a/vs4win/Chapter05/PeopleApp/Program.cs b/vs4win/Chapter05/PeopleApp/Program.cs
index 8e9c6e2..37b75ae 100644
--- a/vs4win/Chapter05/PeopleApp/Program.cs
+++ b/vs4win/Chapter05/PeopleApp/Program.cs
@@ -169,10 +169,11 @@ Book book = new()
 };
 */
 Book book = new(isbn: "978-1803237800",
-  title: "C# 11 and .NET 7 - Modern Cross-Platform Development Fundamentals");
-
-book.Author = "Mark J. Price";
-book.PageCount = 821;
+  title: "C# 11 and .NET 7 - Modern Cross-Platform Development Fundamentals")
+{
+  Author = "Mark J. Price",
+  PageCount = 821
+};
 
 WriteLine("{0}: {1} written by {2} has {3:N0} pages.",
   book.Isbn, book.Title, book.Author, book.PageCount);
diff --git a/vscode/Chapter05/PacktLibraryModern/Book.cs b/vscode/Chapter05/PacktLibraryModern/Book.cs
index cfbfa51..78c2ed2 100644
--- a/vscode/Chapter05/PacktLibraryModern/Book.cs
+++ b/vscode/Chapter05/PacktLibraryModern/Book.cs
@@ -7,7 +7,7 @@ public class Book
   public Book() { } // For use with initialization syntax.
 
   [SetsRequiredMembers]
-  public Book(string isbn, string title)
+  public Book(string? isbn, string? title)
   {
     Isbn = isbn;
     Title = title;
diff --git a/vscode/Chapter05/PeopleApp/Program.cs b/vscode/Chapter05/PeopleApp/Program.cs
index 8e9c6e2..37b75ae 100644
--- a/vscode/Chapter05/PeopleApp/Program.cs
+++ b/vscode/Chapter05/PeopleApp/Program.cs
@@ -169,10 +169,11 @@ Book book = new()
 };
 */
 Book book = new(isbn: "978-1803237800",
-  title: "C# 11 and .NET 7 - Modern Cross-Platform Development Fundamentals");
-
-book.Author = "Mark J. Price";
-book.PageCount = 821;
+  title: "C# 11 and .NET 7 - Modern Cross-Platform Development Fundamentals")
+{
+  Author = "Mark J. Price",
+  PageCount = 821
+};
 
 WriteLine("{0}: {1} written by {2} has {3:N0} pages.",
   book.Isbn, book.Title, book.Author, book.PageCount);