diff --git a/vs4win/Chapter06/NullHandling/NullHandling.csproj b/vs4win/Chapter06/NullHandling/NullHandling.csproj
index 6431db6..aae55a2 100644
--- a/vs4win/Chapter06/NullHandling/NullHandling.csproj
+++ b/vs4win/Chapter06/NullHandling/NullHandling.csproj
@@ -7,8 +7,8 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
-	<ItemGroup>
-		<Using Include="System.Console" Static="true" />
-	</ItemGroup>
+  <ItemGroup>
+    <Using Include="System.Console" Static="true" />
+  </ItemGroup>
 
 </Project>