diff --git a/projects/openttd_vs141.vcxproj b/projects/openttd_vs141.vcxproj
--- a/projects/openttd_vs141.vcxproj
+++ b/projects/openttd_vs141.vcxproj
@@ -724,6 +724,7 @@
     <ClCompile Include="..\src\core\geometry_func.cpp" />
     <ClInclude Include="..\src\core\geometry_func.hpp" />
     <ClInclude Include="..\src\core\geometry_type.hpp" />
+    <ClInclude Include="..\src\core\kdtree.hpp" />
     <ClCompile Include="..\src\core\math_func.cpp" />
     <ClInclude Include="..\src\core\math_func.hpp" />
     <ClInclude Include="..\src\core\mem_func.hpp" />