diff --git a/projects/openttd.vcproj b/projects/openttd.vcproj
index b86376c874..108990791f 100644
--- a/projects/openttd.vcproj
+++ b/projects/openttd.vcproj
@@ -455,6 +455,9 @@
 			<File
 				RelativePath=".\..\src\heightmap.h">
 			</File>
+			<File
+				RelativePath=".\..\src\helpers.hpp">
+			</File>
 			<File
 				RelativePath=".\..\src\industry.h">
 			</File>
diff --git a/projects/openttd_vs80.vcproj b/projects/openttd_vs80.vcproj
index d7a2064083..e2bba363ec 100644
--- a/projects/openttd_vs80.vcproj
+++ b/projects/openttd_vs80.vcproj
@@ -738,6 +738,9 @@
 			<File
 				RelativePath=".\..\src\heightmap.h">
 			</File>
+			<File
+				RelativePath=".\..\src\helpers.hpp">
+			</File>
 			<File
 				RelativePath=".\..\src\industry.h">
 			</File>
diff --git a/source.list b/source.list
index e7247a7b8c..0204e01cd7 100644
--- 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