diff --git a/src/xpdev/xpdev_mt.dsp b/src/xpdev/xpdev_mt.dsp
index cb5fea3ed3fdd432dae42b70417519868210f258..5c1844582565fac9f0c1152bb0e87e44667ee008 100644
--- a/src/xpdev/xpdev_mt.dsp
+++ b/src/xpdev/xpdev_mt.dsp
@@ -134,6 +134,10 @@ SOURCE=.\threadwrap.c
 # End Source File
 # Begin Source File
 
+SOURCE=.\xp_dl.c
+# End Source File
+# Begin Source File
+
 SOURCE=.\xpdatetime.c
 # End Source File
 # Begin Source File