diff --git a/eval.ml b/eval.ml
index d5fd1a2..478f95b 100644
--- a/eval.ml
+++ b/eval.ml
@@ -101,10 +101,10 @@ let rec binop op l r =
     end
   | Some f -> f l r
 
-let deg r =
+let rad r =
   r *. 180. /. Float.pi
 
-let rad d =
+let deg d =
   d /. 180. *. Float.pi
 
 let floatfun f = function