diff --git a/luasocket.vcproj b/luasocket.vcproj
index 9424810..73d8322 100644
--- a/luasocket.vcproj
+++ b/luasocket.vcproj
@@ -145,6 +145,9 @@
 			<File
 				RelativePath=".\select.c">
 			</File>
+			<File
+				RelativePath=".\smtp.c">
+			</File>
 			<File
 				RelativePath=".\tcp.c">
 			</File>