diff --git a/projects/openttd.vcproj b/projects/openttd.vcproj
--- a/projects/openttd.vcproj
+++ b/projects/openttd.vcproj
@@ -456,6 +456,9 @@
 				RelativePath=".\..\src\heightmap.h">
 			</File>
 			<File
+				RelativePath=".\..\src\helpers.hpp">
+			</File>
+			<File
 				RelativePath=".\..\src\industry.h">
 			</File>
 			<File
diff --git a/projects/openttd_vs80.vcproj b/projects/openttd_vs80.vcproj
--- a/projects/openttd_vs80.vcproj
+++ b/projects/openttd_vs80.vcproj
@@ -739,6 +739,9 @@
 				RelativePath=".\..\src\heightmap.h">
 			</File>
 			<File
+				RelativePath=".\..\src\helpers.hpp">
+			</File>
+			<File
 				RelativePath=".\..\src\industry.h">
 			</File>
 			<File
diff --git a/source.list b/source.list
--- a/source.list
+++ b/source.list
@@ -112,6 +112,7 @@ gfxinit.h
 gui.h
 hal.h
 heightmap.h
+helpers.hpp
 industry.h
 livery.h
 macros.h