diff --git a/src/pathfinder/npf/aystar.h b/src/pathfinder/npf/aystar.h
--- a/src/pathfinder/npf/aystar.h
+++ b/src/pathfinder/npf/aystar.h
@@ -75,7 +75,7 @@ struct AyStar;
  *  - #AYSTAR_FOUND_END_NODE : indicates this is the end tile
  *  - #AYSTAR_DONE : indicates this is not the end tile (or direction was wrong)
  */
-typedef int32 AyStar_EndNodeCheck(AyStar *aystar, OpenListNode *current);
+typedef int32 AyStar_EndNodeCheck(const AyStar *aystar, const OpenListNode *current);
 
 /**
  * Calculate the G-value for the %AyStar algorithm.