diff --git a/include/extern.h b/include/extern.h
index 1a71e505e..ccab64021 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -1519,9 +1519,11 @@ extern void gain_guardian_angel(void);
 /* ### mklev.c ### */
 
 extern void sort_rooms(void);
-extern void add_room(int, int, int, int, boolean, schar, boolean);
-extern void add_subroom(struct mkroom *, int, int, int, int, boolean, schar,
-                        boolean) NONNULLARG1;
+extern void add_room(coordxy, coordxy, coordxy, coordxy,
+                     boolean, schar, boolean);
+extern void add_subroom(struct mkroom *,
+                        coordxy, coordxy, coordxy, coordxy,
+                        boolean, schar, boolean) NONNULLARG1;
 extern void free_luathemes(enum lua_theme_group);
 extern void makecorridors(void);
 extern void add_door(coordxy, coordxy, struct mkroom *) NONNULLARG3;
diff --git a/src/mklev.c b/src/mklev.c
index a209cf371..def62d5e0 100644
--- a/src/mklev.c
+++ b/src/mklev.c
@@ -215,7 +215,7 @@ do_room_or_subroom(struct mkroom *croom,
 }
 
 void
-add_room(int lowx, int lowy, int hix, int hiy,
+add_room(coordxy lowx, coordxy lowy, coordxy hix, coordxy hiy,
          boolean lit, schar rtype, boolean special)
 {
     struct mkroom *croom;
@@ -229,7 +229,9 @@ add_room(int lowx, int lowy, int hix, int hiy,
 }
 
 void
-add_subroom(struct mkroom *proom, int lowx, int lowy, int hix, int hiy,
+add_subroom(struct mkroom *proom,
+            coordxy lowx, coordxy lowy,
+            coordxy hix, coordxy hiy,
             boolean lit, schar rtype, boolean special)
 {
     struct mkroom *croom;