diff --git a/flap/src/hopix/hopixTypechecker.ml b/flap/src/hopix/hopixTypechecker.ml
index 6d64811..c17f29e 100644
--- a/flap/src/hopix/hopixTypechecker.ml
+++ b/flap/src/hopix/hopixTypechecker.ml
@@ -183,7 +183,7 @@ and synth_define
 and synth_ref
   : HopixTypes.typing_environment -> expression Position.located -> HopixTypes.aty
   =
-  fun tenv expr -> failwith "Students! This is your job! (synth_ref)"
+  fun tenv expr -> HopixTypes.href (synth_expression tenv expr)
 
 and synth_assign
   :  HopixTypes.typing_environment -> expression Position.located