diff --git a/src/passes/operators/operators.ml b/src/passes/operators/operators.ml
index 6638c352e..06999bded 100644
--- a/src/passes/operators/operators.ml
+++ b/src/passes/operators/operators.ml
@@ -76,6 +76,7 @@ module Simplify = struct
       ("string_slice" , "SLICE") ;
       ("bytes_concat" , "CONCAT") ;
       ("bytes_slice" , "SLICE") ;
+      ("bytes_pack" , "PACK") ;
       ("set_empty" , "SET_EMPTY") ;
       ("set_mem" , "SET_MEM") ;
       ("set_add" , "SET_ADD") ;