diff --git a/tilde-train.py b/tilde-train.py
index fafb26c..39902e0 100755
--- a/tilde-train.py
+++ b/tilde-train.py
@@ -187,14 +187,14 @@ def test_user_car():
   print("PASS. Your train car will work on the tilde.town tracks! :)")
   sys.exit()
 
-def link_car(car):
+def link_car(car: list[str]):
   for idx,row in enumerate(car):
     car[idx] = " " + row
   car[len(car)-3] = "+" + car[len(car)-3][1:]
   car[len(car)-2] = "+" + car[len(car)-2][1:]
   return car
 
-def validate_car(car):
+def validate_car(car: list[str]):
 ## this function (1) checks that a train car isn't too tall or too long
 ## (2) pads it vertically or on the right side if it is too short or if
 ## not all lines are the same length and (3) removes bad characters.
@@ -257,7 +257,7 @@ def print_all_cars():
 #      print "Cannot open " + fname # for debuggering purposes
 
 
-def chuggachugga(stdscr):
+def chuggachugga(stdscr: curses.window):
   curses.curs_set(0)
   h, w = stdscr.getmaxyx()
   x_pos = w-1