diff --git a/openttd.dsp b/openttd.dsp
--- a/openttd.dsp
+++ b/openttd.dsp
@@ -91,7 +91,7 @@ LINK32=link.exe
 # PROP Default_Filter "cpp;c;cxx;rc;def;r;odl;idl;hpj;bat"
 
 # Begin Source File
-SOURCE=.\ai.c
+SOURCE=.\ai_old.c
 # End Source File
 
 # Begin Source File
@@ -375,7 +375,7 @@ SOURCE=.\window.c
 # PROP Default_Filter "h;hpp;hxx;hm;inl"
 
 # Begin Source File
-SOURCE=.\ai.h
+SOURCE=.\ai_new.h
 # End Source File
 
 # Begin Source File