diff --git a/test/test_projet_pfa_23_24.ml b/test/test_projet_pfa_23_24.ml
index 5e3f434..b675b7b 100644
--- a/test/test_projet_pfa_23_24.ml
+++ b/test/test_projet_pfa_23_24.ml
@@ -42,6 +42,10 @@ let tests_typeof =
     , Some Type.(Arrow (Int, Arrow (Int, Int))) )
   ; (* Use of a non declared variable *)
     "fun x -> fun y -> y / z", Term.(Fun (x, Fun (y, Binop (Var y, Div, Var z)))), None
+    (* Type mismatch between argument and function *)
+  ; ( "(fun x -> x + 1) true"
+    , Term.(App (Fun (x, Binop (Var x, Plus, IntConst 1)), Var x))
+    , None )
   ]
 ;;