diff --git a/Makefile b/Makefile
index 8339749d19..7a17f357e0 100644
--- a/Makefile
+++ b/Makefile
@@ -603,7 +603,7 @@ endif
 
 ### Sources
 
-C_SOURCES += ai.c
+C_SOURCES += ai_old.c
 C_SOURCES += ai_build.c
 C_SOURCES += ai_new.c
 C_SOURCES += ai_pathfinder.c
diff --git a/ai_build.c b/ai_build.c
index 0b97a0eb90..569783d458 100644
--- a/ai_build.c
+++ b/ai_build.c
@@ -4,7 +4,7 @@
 #include "map.h"
 #include "tile.h"
 #include "command.h"
-#include "ai.h"
+#include "ai_new.h"
 #include "engine.h"
 #include "station.h"
 
diff --git a/ai_new.c b/ai_new.c
index 17a010b2b6..ec122ba1f0 100644
--- a/ai_new.c
+++ b/ai_new.c
@@ -22,7 +22,7 @@
 #include "map.h"
 #include "tile.h"
 #include "command.h"
-#include "ai.h"
+#include "ai_new.h"
 #include "town.h"
 #include "industry.h"
 #include "station.h"
diff --git a/ai.h b/ai_new.h
similarity index 100%
rename from ai.h
rename to ai_new.h
diff --git a/ai.c b/ai_old.c
similarity index 100%
rename from ai.c
rename to ai_old.c
diff --git a/ai_pathfinder.c b/ai_pathfinder.c
index b4bcbb5e52..f6e2c3f579 100644
--- a/ai_pathfinder.c
+++ b/ai_pathfinder.c
@@ -4,7 +4,7 @@
 #include "map.h"
 #include "tile.h"
 #include "command.h"
-#include "ai.h"
+#include "ai_new.h"
 #include "depot.h"
 
 #define TEST_STATION_NO_DIR 0xFF
diff --git a/ai_shared.c b/ai_shared.c
index 86e964086c..ea9fdb9d57 100644
--- a/ai_shared.c
+++ b/ai_shared.c
@@ -2,7 +2,7 @@
 #include "openttd.h"
 #include "debug.h"
 #include "map.h"
-#include "ai.h"
+#include "ai_new.h"
 #include "vehicle.h"
 
 int AiNew_GetRailDirection(TileIndex tile_a, TileIndex tile_b, TileIndex tile_c)
diff --git a/openttd.c b/openttd.c
index ffdced635a..8a88789adb 100644
--- a/openttd.c
+++ b/openttd.c
@@ -27,7 +27,7 @@
 #include "fileio.h"
 #include "hal.h"
 #include "airport.h"
-#include "ai.h"
+#include "ai_new.h"
 #include "console.h"
 #include "screenshot.h"
 #include "network.h"
diff --git a/openttd.dsp b/openttd.dsp
index 13518f8ac3..7b6efc9a08 100644
--- 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
diff --git a/openttd.tgt b/openttd.tgt
index da208e9882..89d7ba8ad0 100644
--- a/openttd.tgt
+++ b/openttd.tgt
@@ -412,7 +412,7 @@ WVList
 105
 MItem
 4
-ai.c
+ai_old.c
 106
 WString
 4
diff --git a/openttd.vcproj b/openttd.vcproj
index 1c43864bc5..1692471be4 100644
--- a/openttd.vcproj
+++ b/openttd.vcproj
@@ -161,7 +161,7 @@
 			Name="Source Files"
 			Filter="cpp;c;cxx;rc;def;r;odl;idl;hpj;bat">
 			<File
-				RelativePath="ai.c">
+				RelativePath="ai_old.c">
 			</File>
 			<File
 				RelativePath=".\airport.c">
@@ -737,7 +737,7 @@
 			Name="AI Files"
 			Filter="">
 			<File
-				RelativePath=".\ai.h">
+				RelativePath=".\ai_new.h">
 			</File>
 			<File
 				RelativePath=".\ai_build.c">
diff --git a/openttd.xcode/project.pbxproj b/openttd.xcode/project.pbxproj
index bc73d28a89..82f48279cc 100644
--- a/openttd.xcode/project.pbxproj
+++ b/openttd.xcode/project.pbxproj
@@ -3111,7 +3111,7 @@
 			fileEncoding = 30;
 			isa = PBXFileReference;
 			lastKnownFileType = sourcecode.c.h;
-			path = ai.h;
+			path = ai_new.h;
 			refType = 2;
 			sourceTree = SOURCE_ROOT;
 		};
@@ -3119,7 +3119,7 @@
 			fileEncoding = 30;
 			isa = PBXFileReference;
 			lastKnownFileType = sourcecode.c.c;
-			path = ai.c;
+			path = ai_old.c;
 			refType = 2;
 			sourceTree = SOURCE_ROOT;
 		};
diff --git a/players.c b/players.c
index 4960a93277..590e2f66ae 100644
--- a/players.c
+++ b/players.c
@@ -15,7 +15,7 @@
 #include "news.h"
 #include "saveload.h"
 #include "command.h"
-#include "ai.h"
+#include "ai_new.h"
 #include "sound.h"
 #include "network.h"