diff --git a/ttd.dsp b/ttd.dsp
index 4b2aef0b35..db6b883fef 100644
--- a/ttd.dsp
+++ b/ttd.dsp
@@ -216,6 +216,10 @@ SOURCE=.\landscape.c
 # End Source File
 # Begin Source File
 
+SOURCE=.\map.c
+# End Source File
+# Begin Source File
+
 SOURCE=.\md5.c
 # End Source File
 # Begin Source File
@@ -470,6 +474,10 @@ SOURCE=.\macros.h
 # End Source File
 # Begin Source File
 
+SOURCE=.\map.h
+# End Source File
+# Begin Source File
+
 SOURCE=.\md5.h
 # End Source File
 # Begin Source File