diff --git a/Visual Studio Projects/AltairZ80.vcproj b/Visual Studio Projects/AltairZ80.vcproj
index cd98a3a5..2bb4fbbe 100644
--- a/Visual Studio Projects/AltairZ80.vcproj	
+++ b/Visual Studio Projects/AltairZ80.vcproj	
@@ -321,6 +321,10 @@
 				RelativePath="..\AltairZ80\s100_dj2d.c"
 				>
 			</File>
+			<File
+				RelativePath="..\AltairZ80\s100_djhdc.c"
+				>
+			</File>
 			<File
 				RelativePath="..\AltairZ80\s100_fif.c"
 				>