diff --git a/flap/src/hopix/hopixTypechecker.ml b/flap/src/hopix/hopixTypechecker.ml
index 6cd68ff..694c74f 100644
--- a/flap/src/hopix/hopixTypechecker.ml
+++ b/flap/src/hopix/hopixTypechecker.ml
@@ -216,7 +216,15 @@ and synth_ifthenelse
   :  HopixTypes.typing_environment -> expression Position.located
   -> expression Position.located -> expression Position.located -> HopixTypes.aty
   =
-  fun tenv ecase eif eelse -> failwith "Students! This is your job! (synth_ifthenelse)"
+  fun tenv ecase eif eelse ->
+  (* Pas testé !! *)
+  let ecasety = synth_expression tenv ecase in
+  check_equal_types ecase.position ~expected:ecasety ~given:HopixTypes.hbool;
+  let eifty = synth_expression tenv eif in
+  check_equal_types eif.position ~expected:eifty ~given:HopixTypes.hunit;
+  let eelsety = synth_expression tenv eelse in
+  check_equal_types eelse.position ~expected:eelsety ~given:HopixTypes.hunit;
+  HopixTypes.hunit
 
 and synth_while
   :  HopixTypes.typing_environment -> expression Position.located