diff --git a/lib/ansi.ml b/lib/ansi.ml
index cac51fc..1deeea8 100644
--- a/lib/ansi.ml
+++ b/lib/ansi.ml
@@ -6,8 +6,6 @@ and color = R | G | Y | U | C
 
 type t = ctl list
 
-external int_of_color : color -> int = "%identity"
-
 let string_of_ctl = function
   | Bold true   -> "1"
   | Bold false  -> "22"