diff --git a/src/autoslope.h b/src/autoslope.h
--- a/src/autoslope.h
+++ b/src/autoslope.h
@@ -14,7 +14,6 @@
 
 #include "company_func.h"
 #include "depot_func.h"
-#include "slope_func.h"
 #include "tile_map.h"
 
 /**