diff --git a/openttd.dsp b/openttd.dsp
--- a/openttd.dsp
+++ b/openttd.dsp
@@ -284,6 +284,10 @@ SOURCE=.\newgrf_engine.c
 # End Source File
 # Begin Source File
 
+SOURCE=.\newgrf_spritegroup.c
+# End Source File
+# Begin Source File
+
 SOURCE=.\newgrf_station.c
 # End Source File
 # Begin Source File
@@ -646,6 +650,10 @@ SOURCE=.\newgrf_engine.h
 # End Source File
 # Begin Source File
 
+SOURCE=.\newgrf_spritegroup.h
+# End Source File
+# Begin Source File
+
 SOURCE=.\newgrf_station.h
 # End Source File
 # Begin Source File